There are many different methods for distance measuring, and the laser measuring techniques, as a technology for precision measurement, are widely used in the military field and the civil field in which high accuracy is needed. In order to solve the laser measurement problems caused by laser source excursion, the environment and optical components aberration in the light path, a novel compensated beam-split technique for laser measurement is proposed. Because compensation beam-spilt technique(CBST) is used to compensate the beam excursion caused by the laser itself and disturb of the environment, steady four light beams are obtained in which have equal intensity and phase in the experiment; the effect of CBST has been proved in the laser measurement experiment.

Simulating star magnitude value and its precision is the key for inspecting the detectivity of calibrated optical measuring equipment. The principles of simulating magnitudes of space target scene simulator (STSS) are proposed at first. Based on Planck blackbody radiation law, the causal model of the simulated magnitudes and luminous flux, photon flux in the inner field is deduced, and the major factors that influence the magnitudes value are analyzed. A relative measuring method is used to scale the star magnitudes of STSS on the basis of considering the difficulties of scaling the dark star magnitudes. Afterward, all magnitude error factors, which will arise the simulate magnitude fluctuation, are pointed out. Finally, the theoretic formula of the simulating magnitudes precision error is worked out for the relative measuring method. Experimental results show that the scale ability of STSS achieves 12m magnitudes, and magnitudes error is less than ±0.2m.

During the real-time interferometry, the phase measurement error may be caused by any of the ambient temperature fluctuation and air turbulence and the drift of the system inner parameters, especially in high-accuracy survey occasion,the influence of this error is especially obvious. Therefore, this paper put forward a filtering phase discrimination LD real-time SPM surface profile interferometry insensitive to disturbance, clarified their operating principle. This feedback control system takes out the interference signal of one measured point from the total interference signal as a feedback signal, then injects it into the semiconductor laser to make its wavelength change. So the phase error caused by external interference is reduced to the negligible degree, and the influence to the measurement accuracy caused by external interference is sharply reduced. And the normalization technology is used to eliminate the influence to the measurement accuracy caused by system inner parameters’ drift . For 70×70 measured points, its repeatable measurement precision is about 3 nm , measuring time is less than 12 ms.

Geometric parameters of multifold fiber are measured, and an exact and applied fiber diameter measurement method is proposed based on the digital image processing. The method acquires the fiber picture via optical microscopy system and image acquisition system, and then processes the data via data fitting by computer. The diameter of vacant core fiber and non-communications fiber is measured, and then the data error is analyzed. The experimental results show that the proposed method is simple and easy, and it can be applied to some special areas where direct measurement is unfeasible.

Charge detection quadrupole ion trap (QIT) mass spectrometry (MS) is an effective technique for high-speed mass analysis of micron-sized particles such as biological cells and aerosols. In this technique, the trap can be operated by scanning the frequency of the ac field under a low-vacuum condition. This paper describes a calibration method which involves determination of the points of ejection (qeject) of the individual particles to be analyzed how the ejection points vary with the pressure of buffer gas. Using NIST polystyrene size as the test samples, a mean ejection point of qeject =0.952 is attained at the trap driving voltage amplitude of 1617 V, with He buffer gas pressure of 5.33 Pa, and a frequency scan rate of 70 Hz/s over the scan range of 450～100 Hz. The mean value (0.947) of qeject is measured without the buffer gas. The result indicates the buffer gas has an effect on the ejection point of particle in the trap.

Absorption spectra of 11 illicit drugs were measured by using the terahertz time-domain spectroscopy technique (THz-TDS) in the range 0.2～2.6 THz, and then the absorption spectra of the 11 different illicit drugs were identified successfully by well trained radial basis function (RBF) neural networks. The spectra used for training and identification were normalized before input to the network and the positive identification rate is 96%. The model of RBF neural network was processed in Matlab. The results indicate that it is feasible to apply RBF neural network to the identification of illicit drugs, and the speed of training and identification is fast. The character makes RBF network superior to back propagation neural network (BP) and self-organizing feature map (SOM). Therefore, RBF neural network provides a fast and effective method in the secure inspection and identification for illicit drugs using THz-TDS technique.

The optic system temperature distribution that is solved by finite element method with the software of I-DEAS ,that will descend the image quality in star sensor if it is not uniform. The effects of the outside and inside surface coat, the angle of sun incidence, the heat conduction of the drawtube and the thermal joint conduction on temperature distribution have been analyzed. It is shown that, the average temperature of system is decided by the outside and inside surface coat and the angle of sun incidence. The temperature difference is decided by the heat conduction of the drawtube and the thermal joint conduction. It is found that, when the ratio of absorptance and emittance of outside surface coat change from 0.25 to 4, the average temperature is from -78.10 ℃ to 66.53 ℃. When the emissivity of inside surface coat change from 0.2 to 1, the average temperature is from 25.00 ℃ to 18.22 ℃. When the angle of sun incidence change from -60° to 0°, the average temperature is from -9.59 ℃ to 18.22 ℃. When the drawtube is the alloy of titanium or aluminum, the temperature difference is 6.85 ℃ and 0.31 ℃. When the thermal conductivity of the thermal joint conduction is 237 W/(m·k), the temperature difference is 2.37 ℃. The conclusion has great c significance to the engineering.

The diffusion light detected from bio-tissue surface contains tissue optical parameters information. So tissue optical parameters can be obtained indirectly by the diffusion light measuring, then optical parameters resolved tissue structure, physiology and pathology state information can be obtained finally. A multi-distance measurements method is employed in this paper. A single parameter (reduced scattering coefficient) fitting method and a double parameters (reduced scattering coefficient and amplitude factor) fitting method on the basis of the least square Newton fitting algorithm is used to derive the optical parameters respectively. For the finite-thickness homogenous tissue, it can be concluded that the rest terms in expressions of diffusion reflectance and transmittance for the corresponding tissue geometries that subtract the exponential term contained source-detector distance depend on the detected position weakly. And some discussions are included. Additionally, the probable structure information for the finite-thickness two-layered slab tissue can be obtained from the diffusion reflectance and transmittance measurements according to the discrepancies of fitting reduced scattering coefficient and the sign (positive or negative) of the amplitude factor.

Current responsivity is an important characteristic of UV detector which cannot be measured directly after the coupling between detector array and readout integrated circuit (ROIC) chip. It’s very significant on the measurement for current responsivity of UV Focal plane array (FPA) detector. The 128×1 ROIC chip were measured. The integration capacitance and gain of source follower of ROIC chip were analyzed. Then, 128×1 AlGaN photosensitive chip and 128×1 UV FPA detector were tested by using a special system which was developed independently for high-accuracy measurement of UV detector. An indirect test method for current resposivity of UV FPA detector was studied and set up. The current responsivities by testing photosensitive chip directly were basically consistent with those by testing UV FPA indirectly. The relative deviation is about 5%. This test method is very easy and reliable, so can provide significant parameters to the comprehensive evaluation of UV FPA.

Some mathematics models are made to analyze some important errors in this paper firstly, and the result shows that the most important error is the measurement error of interferometer. Then the way in which the error of interferometer influences the accuracy of stitching is studied. The matrix singular value decomposition (SVD) is introduced in this paper to deal with the ill-conditioned equation series to reduce the effect of the most important error, while the contrast data is done with QR arithmetic. The result reveals that the SVD is useful in high accuracy sub-apertures stitching, and can decrease the requirement to high accuracy equipment.

Terahertz time-domain spectroscopy has been used to measure the absorption spectra and the indexes of refraction of vitamin B1, B2, B6 and B12, which are vital to human beings. Experimentally, from comparison, it is found that they have different fingerprint spectra. Theoretically, the molecule structure of the samples are optimized using density functional theory (DFT) and then these frequencies are calculated. The optimized molecular structure and vibration frequencies of three kinds of the samples are obtained; the results are in agreement with simulation. The simulation results show that most of the vibration frequencies are caused by the torsion and wagging of the molecular, others are caused by intermolecular or phonon mode. This study not only provides better theoretical and experimental methods, but also be helpful to the detection of vitamins with spectra.

In recent years, split ring resonator (SRR) is a new micro-structure of the array. The resonance transmission and absorption effect of the split ring aroused a great deal of concern. It's mainly the two kinds, one is square, the other is round, and all of them with a ring slit. This micro-structure can be seen as the wires array, it will produce the clear electromagnetic response under the time-varying electric and magnetic fields. Utilizing terahertz time domain spectroscopy system, the research by changing angles of terahertz electric wave vector with split of split ring, found that different modes of dipole oscillating are made by changing electric wave vector, and its absorption is also affected. However, natural frequency of SRR is decided by lattice size, independent of transmission mode. Infections to resonance properties of SRR by terahertz electric wave vectors are discussed in this letter. It can be a reference for researching terahertz devices.

Experimental measurement and theoretical analysis of terahertz spectrum for one pure material and some mixed explosive samples are introduced. The refractive index and absorption coefficient of the samples are measured in the region of 0.2～2.5 THz by time-domain spectroscopy(THz-TDS). The absorption spectra are obtained correspondingly. Results indicate that the THz-TDS technology can identify the different explosives and roughly analyse the main ingredients of the mixed samples.

In order to study the spectroscopic characters of explosives in the terahertz region and realize the identification of explosives, the terahertz absorption spectra of explosives have been measured by using terahertz time-domain spectroscopy (THz-TDS) system. These samples which include pure explosives RDX, HMX,DNT,PETN, TNPG and mixed explosives 8701,PW0,R791,R852,SU-1,8702 were then identified by two types of artificial neural networks(ANNs)—self-organized mapping(SOM)and muti-layer perceptron(MLP)—through repetitive modeling and adequate training. High positive identification rate (above 95%) and low false alarm rates have been gained. The results indicate that it is feasible to apply these two ANNs on the identification of different types of explosives, and it also provides an effective method in the inspection and identification for explosives using THz-TDS.

Using a new terahertz reflective-transimission design suite (TDS) system, various agricultural chemical solution were measured. A series of reflectivity spectra of agricultural chemical solution were obtained. The relation between reflection ratio and concentration of the solution was drawn. A new method for measuring the concentration of agricultural chemical solution with terahertz reflective-TDS was proposed. This method is expected to be used in the environmental pollution monitoring and manufacture quality controlling.

Using the analysis model of the phase noise, the random noise of semiconductor laser is studied. The modulation on the phase and complex amplitude of laser is discussed. A beat note experiment system with two different kind of laser is established to get the noise signal. In the system, a tunable semiconductor laser and a fiber laser are employed. Since the linewidth of fiber laser is much narrower than that of the semiconductor laser, the beat note can show the noise character of the semiconductor laser. According to the statistic character of the laser phase noise, a kind of phase lock technique is introduced. The feasibility of such scheme is studied in detail.

The spectral behavior of polychromatic spatially fully coherent light diffracted by an annular aperture in near field is studied in this paper basing on the research of it in the far field. Detailed numerical calculation results are presented and illustrated. It is shown that the spectrum in the near field is generally different from that at the aperture. It is proportional to the spectrum at the aperture and a spectral modifier which depends on the central obstruction ratio ε, the distance z between the aperture and the observe point and the distance r of the observe point to the z axes. With the increase of the central obstruction ratio ε, the spectrum of near field translates into far field gradually. Detailed numerical calculation results indicate that significant spectral changes take place in the vicinity of intensity zeros (These corresponding points are singularities), i.e., the spectrum is red-shifted at the side of the singularities, blue-shifted at the other side of the singularities and exhibits a rapid transition at the positions of the singularities between them.

Visibility is one of the most important gists in military area. For example, airplane and ships’ safely navigating need this parameter, demarcating radar or photoelectric equipment needs it and all the military strike needs it too. In this paper, the definiens of the visibility was first expatiated, and then the measurements of the visibility detecting and the theory of it were illuminated, including imaging method, aerosol sampling method, optical parameter calculating method and so on. Except that, the character and the applying area were discussed. In the end, a conclusion was pointed that visibility detecting with backscatter signal would become emphases in the future study.

The movement of nanoparticles in fluids is one of the main factors that result in the remarkable thermal conductivity of nanofluids. In this paper, Laser speckle velocimetry (LSV) is proposed to measure the velocities of nanoparticles in nanofluids, and traditional LSV system is modified in order to be competent for detecting the movements of nanoparticles. It is verified that speckles can indeed be formed by illuminating laser beam on nanofluids by the means of experiments and numerical simulations. According to the modified experimental setup, a physical model is established. Based on statistical properties of speckles, the relationship between the movements of nanoparticles and the movements of speckles on the screen is studied by formula deduction. A conclusion is drawn that the velocities of nanoparticles is identical to the velocities of speckles in Fresnel region. Thereafter, the experimental system is set up, and speckle patterns sequences are recorded with high speed CCD camera. Two consecutive speckle patterns are processed with computer programs to obtain the motion vector diagram of speckles, thereby the motion of nanoparticles.

Based on computational fluid dynamics (CFD) software FLUENT, a 2-D model is developed for the calculation of UV radiation from rocket plume. The solid rocket exhaust plume is composed of hot reactive gases and metallic oxide particles like alumina. Calculations take into account the chemiluminence reaction of CO+O, which is the dominant source of radiation in the UV wavelength band considered, and particle emission-scattering effects produced by alumina particles. The size distribution of alumina particle is assumed to be Rosin-Rammler distribution, and the scattering effect from gas is excluded, and absorption coefficient is calculated through weighted sum of gray gases model (WSGGM). The radiation transport equation (RTE) is solved by the discrete ordinate method (DOM). Finally, the simulation result is compared with Fillip’s(Ref.[1]).

The relative change between inflection points of respiratory quotient (RQ) and HbO2 in skeletal muscle during the process of increased intensity sports is investigated. The occurrence priority and interval regularity of the two based on time is compared, and the physiological mechanism of synchronisms is analyzed. 12 rowing athlete candidates are chosen to test to do increased intensity sports on dynamometer (CONCEPT Ⅱ). The output power of initial load is 50 W, and then increased by 50 W every 3 min until exhaustive. The relative changes of HbO2 in Quadriceps by near-infrared spectroscopy (NIRS) during sports are monitored. Simultaneously the oxygen uptake of candidates in sports is determined and recorded, including the intake of oxygen (VO2) and exhaled volume of carbon dioxide (VCO2) by the Cardiopulmonary Function Instrument MAX-Ⅱ. The inflection point of RQ is relatively changing to ΔHbO2. That means there is a time delay in RQ. The delay in VO2 and VCO2 relative to HbO2, which is affirmed in the single-factor variance analysis test, is do exist. During increased intensity sports, the respiratory quotient changes regularly accompanied with the inflection point, and content of muscle oxygen (ΔHbO2) in quadriceps changes regularly with unconventional inflection point which might denote that of respiratory quotient. Inflection point of respiratory quotient has a regular delay time relative to that of ΔHbO2. The phenomenon provides powerful evidence for us to speculate inflection point of respiratory quotient by measuring ΔHbO2 in Muscle-Oxygen Monitoring System. It may provide new methods to measure oxygen uptake.

Reactive oxygen species (ROS) can damage molecules such as lipids and proteins, thus cause oxidative damages to cells. During photosensitization process such as photodynamic therapy (PDT), a large amount of ROS is produced. By monitoring the ROS production, it is possible to evaluate the oxidation caused by ROS and the subsequent biological outcome by a PDT treatment. Results indicate that, there is a long-life delayed chemiluminescence (CL) after the human serum oxidized with photosensitization. This property may be used to monitor CL after turning off the excitation light source, thus achieve a high signal/noise ratio in detection. With the delayed CL detection method, CL was evaluated with various photosensitizes. The technique was also tested in vitro, it was found that the CL signal was readily detectable and showed a linear relationship with the dose of PDT treatment. In conclusion, the detection of real-time CL is tested both in solutions doped with various photosensitizes and in vitro and the cumulated CL can be used as a marker for evaluating the damage to biologic molecule and cell. This method can be used on photosensitization such as photodynamic therapy to monitor the dose.

Based on the traditional Michelson interferometer,the four-channel balancing method for micro-vibration measurement system is built. The method without using PZT to generate high frequency carrier wave realizes four orthogonal signals by using four-channel-balancing detection instead of using PGC demodulation circuit. This method overcomes the nonlinearity of PZT, simplifies the demodulation circuit,and reduces the intensity noise of laser source, simultaneously. Through the Lissajou figure which is synthesized by the four signals, the four signals are proved to be orthogonal. The experimental results show that this method can realize the measurement of micro-vibration, and the micro-vibration displacements measuring range can be up to 5～775 nm.

This paper aims at range and error calibration of laser speedometer. According to the measurement principle of laser speedometer, one new calibration method and instrument with simulated target is put forward, which provides simulated target with invariable speed to simulate vehicle, and achieve range calibration by changing the speed of simulated target. Experiments show that the calibration instrument can meet the need of laser speedometer calibration because of its wide calibration range, high repeatability and universal performance.

Optical phase measurement depends on the phase reconstruction from fringe patterns to a great extent. Phase reconstruction means to eliminate the discontinuity of phase extracted from fringe patterns. Most phase-reconstructing (PR) algorithms might share a common research interest, namely, to construct an excellent phase-evaluating mechanism——quality map. Hence two kinds of experimental fringe patterns are studied for 3D measurement. It’s found that the gradient variance of log modulation amplitude (GVLMA) could be chosen as a phase indicator. Its reliability could be compared to the traditional phase derivative variance (PDV) quality map. Generally, it’s advised to choose the GVLMA as a guide or weight of PR. For further application, a new composite quality map(log modulation amplitude and phase derivative variance (LMAPDV) has been proposed. It combines the GVLMA and PDV and optimizes the parameter of combination. The LMAPDV could identify the minute defect or badness of phase data which could hardly be recognized by the PDV. Moreover, its identified outlines of poor pixels are much clearer than those of PDV and GVLMA. Then the LMAPDV is introduced into the PR algorithm. The calculated result proves that its solution enjoys higher consistency than that of GVLMA.

As a new imaging technique——optical coherence tomography (OCT) has been widely used in clinical examination. However, the imaging speed and resolution are low. In order to improve the imaging speed and resolution, the sinusoidal-phase modulation OCT detection technology with a high-speed image sensor based on low-speed area array CCD is proposed. A piezoelectric transducer (PZT) is attached on the backside of Michelson interferometer′s reference mirror. A sinusoidal phase signal is used to control the movement of PZT, which makes reference mirror change its reference arm′s optical path as sinusoidal mode along the optical axis direction, thus scans sample′s depth. Light intensity expression of OCT interference signal is deduced, which is based on sinusoidal-phase modulation, and its imaging technology is discussed. One pixel on surface CCD can detect object′s internal fault structure, because PZT shifts phase continuously. Thus, this technique can get the information of sample′s internal fault structure using area array CCD. The technique does not need reference mirror with stepping movement and horizontal mechanical scan, it has lots of advantages, such as fast imaging speed, high sensitivity, high signal-to-noise ratio and low cost.

The optical 8-DPSK is a new modulation format. It has narrower spectrum structure, higher spectrum efficiency, nearly invariable envelope, and better nonlinearity suppression characteristic. According to the principle of 8-DPSK, the modulation and demodulation in the back-to-back system of 8-DPSK is analyzed via simulation. Moreover, the polarization-mode dispersion compensation performance of 8-DPSK is studied. The relationship between the signal’s degree of polarization (DOP) and polarization-mode dispersion (PMD) of different duty-cycle signals is analyzed theoretically and numerically. The result shows that the DOP sensitivity is different among different duty-cycle signals, because the change in duty-cycle results in the change in spectrum structure. In the polarization-mode dispersion compensation system, DOP is adopted as the feedback signal, therefore, the performance of compensation is different among different duty-cycle signals. Through simulation analysis, CSRZ-8-DPSK has the best compensation performance thanks to its narrower spectrum structure and carrier-suppressed characteristic.

Recent progresses of optical code-division multiple access (OCDMA) system are introduced. En/decoders based on fiber Bragg grating (FBG) for 2-dimensional incoherent OCDMA and coherent OCDMA are addressed, using fiber grating arrays and superstructured FBG (SSFBG) as en/decoders respectively, which is most likely to be practical. A novel equivalent phase shift SSFBG is analyzed, the method requires only submicrometer precision to be in control, which reduces the production cost of en/decoder greatly. The principle and comparison of three kind of optical threshold devices, such as nonlinear optical loop mirror, periodically-poled lithium niobate waveguide and dispersion-flattened fiber are emphatically discussed. Optical threshold devices can compress the decoding signal, eliminate the multiple access interference, optimize the detection capability and improve the bit error rate (BER) performance. Coherent OCDMA can produce extremely long and multipolar optical code, while incoherent OCDMA is tunable and have good reconstruction, these two schemes will have great potential application for broadband access network in future.

We theoretically study the slow light based on coherent hole burning in a three-level Λ-type hot atomic system without Doppler-free configurations. With the numerical calculations of the density matrix of the system, the effects of the configuration of the atomic levels, the spontaneous radiation and the dephasing rate on slow light are considered. Due to the coherent effect induced by the coupling field, one can obtain a greater group index by coherent hole burning than that of saturation absorption spectroscopy. Our results are useful to realize the atomic coherence effect, slow light and light storage in diverse hot atomic systems.

A four-level ladder atomic system, driven by two continued fields, is considered. We show that higher coherence and population transfer can be created between the ground state and the meddle excited state. The short wavelength signal can be obtained by stimulated Raman effect when the probe pulse is imployed on the high excited state under steady condition. We show the condition for maximum frequency conversion efficiency by numerical simulation and theoretical analysis, and investigate the influences of the intensity of the two coherent fields,the pulsewidth, the detuning and the various parameters of the atoms on the frequency conversion efficiency.

A complex full-range spectral domain optical coherence tomography system based on spatial sinusoidal phase modulation is presented. Through sinusoidal phase modulation in the reference arm, the quadrature components of interferogram can be obtained by harmonic detecting. Then the complex-conjugate ambiguity, DC term and autocorrelation noise are eliminated by the Fourier transform of complex interferogram. A complex-conjugate rejection ratio of about 35 dB is achieved. Furthermore, in our experiment, high speed complex-conjugate resolved imaging is performed by combining the sinusoidal phase modulation and transversal scanning.

Swept source optical coherence tomography (SSOCT) technique has recently become the hot topic of investigation because of its speed and sensitivity advantage over traditional time domain optical coherence tomography (TDOCT). Based on one dimensional scanning fiber cantilever probe, a SSOCT system is developed. The probe exploits resonance of a fiber cantilever which is excited by one piece of piezoelectric bimorph through a driving signal whose frequency is near the resonant frequency of the fiber cantilever. To achieve a high system axial resolution, the interference spectrum calibration in wave number domain is necessary. We report a calibration method based on Mach-Zender interferometer (MZI), and the system axial resolution achieves 8.3 μm. Based on the fiber cantilever probe, at 20 kHz A-Scan rate, the SSOCT system can get OCT images of sample at a frame rate of 20 frame/s, the lateral range of 1 mm, and the lateral resolution of 10 μm. Some preliminary imaging results presented in the paper demonstrate the feasibility of the scheme.

Temperature-tuned and domain-tuned signal-resonated optical parametric oscillator based on multi-grating periodically poled Mgo-doped lithium niobate and pumped by an acousto-optically (A-O) Q-switched 1064 nm NdYVO4 laser was studied experimentally. The signal wave of 1450～1839 nm could be obtained with poled periods varying from 29.0～31.5 μm and temperature varying from 30～180℃, covering the S+C+L+U wave bands of optical fiber communications, and the range of corresponding idler-wave was 2909～3990 nm. When the pump power was 830 mW, the maximal output power of signal wave was 139.7 mW, the conversion efficiency was 16.8%, and the lowest lasing threshold was 88 mW. The tunable light source has reached the practical power level of optical communications system.

As an important nonlinear optical imaging method, multiphoton excitation has demonstrated its wide application in biomedical imaging. Although shorter pulse can induce a higher nonlinear effect, most applications are still restricted in 100 fs region due to the existence of high-order dispersion. Through the compensation of high-order dispersion with multiphoton intrapulse interference, we successfully introduce 10 fs pulse into multiphoton biomedical imaging. We find that a deeper penetration and a correct excitation of multiple dyes can be obtained with this method.

A continuous-wave (CW) terahertz (THz) standoff scanning imaging system at 0.2 THz is presented. This system works at reflection geometry and the imaging distance is 25 m. A Gunn oscillator is utilized as emitter and an unbiased Schottky diode operated at room temperature is employed as detector. A polyethylene Fresnel lens is used to collimation terahertz wave for standoff propagation. Six aluminum mirrors are employed to increase distance. The sample is placed on an X-Y two-dimensional stage which is controlled by a computer. The collimated THz wave propagates in air and is focused to the sample by another polyethylene Fresnel lens. The back scattered THz wave from the sample surface is collected by the detector alone the same path. The two-dimensional image of sample is obtained by a raster scanning fashion. An aluminum plate with holes, an airplane model and a toy gun contained in a box are imaged at 25 m from the imaging unit. The results show that this standoff imaging system has a wide potential to be applied in the area of security inspection and screening.

The multiplying ability is the greatest advantage of fiber Bragg grating (FBG) sensor, which is easy to realize the large-scale remote measurement system. But at present, the measuring accuracy of optical fiber sensing network constituted by WDM drops obviously when the measuring point quantity increases, and the structure that connected the light source and FBG sensors in series on the same optical fiber reduces the signal-to-noise ratio (SNR) and reliability, and makes the system difficult to expand. In order to solve these problems, a new kind of sensing network called two-fiber sensing network is proposed. The two-fiber sensing network connecte the light source and FBG sensors in parallel between two independent fibers, which increases the SNR, decreases the system fault rate and makes the system easy to expand. At the same time, sensors with same central wave length but different spectrum can be differentiated through the autocorrelation operation of photodiode output signal, which guaranteed the measuring accuracy is not influenced by the measuring point quantity of system. The theoretical analysis and experiment study indicate that the two-fiber sensing network has a fixed SNR and a lower fault rate, and the system’s measuring accuracy is not influenced by its scale, therefore it is a kind of optical fiber sensing network which suits for engineering application.

APEX method is a kind of non-iterative restoration approach, can be applicable to some real-time situation. There is a problem that its result point spread function (PSF) can not be sure energy is conversation in finite support area. The PSF was restrained non-minus and linear unitary based on the APEX method, pointing to the degradation character of opto-electronic image, and the approximate constant A and frequency center domain Ω was improved. At last, reconstruct the restoration image utilizing slow evolution of continuation boundary (SECB) method, give the reference conclusion for how to select the reconstruction factor K and s. The simulation indicates the improved algorithm enhanced its stability, the effect of restoration also has been improved.

The application of off-axis aspheres can improve the imaging quality and the compactness of the optical system furthest. The resolving of the best-fit sphere and the material removal, however, is a very important problem during the fabrications. In this paper, an algorithm available for the precise calculation of the conic and high order off-axis asphere is proposed, considering the requirement of minimum material removal and the slope of material removal. The radius of the best-fit sphere, the maximum material removal and the total volume of material removal are calculated by programming. The advantage of the algorithm is shown by the comparison of results derived from new algorithm and empirical equation. At the same time, the application in the off-axis asphere fabrication also proves the correctness of the algorithm. This algorithm is very helpful for the theory and practice of the fabrications of off-axis asphere.

To improve the high frequency attenuation qualities of the acoustic low-pass filtering underwater fiber-optic acoustic sensors, a new anti-alaising filtering fiber-optic underwater acoustic sensor with a four-order acoustic low-pass filter is proposed, which is based on the two-order structure reported previously. The general low frequency lumped parameters model of the underwater acoustic sensor is constructed based on the theories of electro-acoustic analogy, and the acoustic performance is predicted by the circuit analysis methods. To test the model and the theories, a four-order acoustic low-pass filtering fiber-optic underwater acoustic sensor is fabricated and tested in a standing-wave tube filled with water. Apart from the hight frequency response, the experimental results are well in agreement with the numerical curve. The measured low frequency response is very flat, and the acoustic sensitivity is about -140 dB. The measured two resonant frequencies are in well agreement with the corresponding numerical values, respectively. It is expected that the acoustic low-pass filtering underwater fiber-optic acoustic sensor will become a new class of sensors used to eliminate the aliasing in the future sonar systems.

A device of optical tweezers array based on double-plate shearing interference and its application to separating polystyrene particles are studied. The technique is hopeful to be a novel method of particle separation, such as cells. Firstly, the classical optical tweezers theory is modified to set up theoretical model of optical tweezers array system. The parameters of the model are discussed and simulated by Matlab software to provide the theoretical foundation for the following device design. And an optical tweezers array is set up based on the parameters. With adjusting the angle between two interference fields, a two-dimensional optical tweezers array which has different distribution characters can be obtained. By applying the system to particle trapping, 6 μm polystyrene particles are trapped successfully, which proves the rationality and feasibility of the design.

According to ISO 11146-1: 2005, mode-field half width, far-field divergence half angle and beam propagation factor of the diffractive beam from TE0 mode in planar waveguide are analyzed by a new method. Under the condition of paraxial approximation, formulas of diffractive beam parameters as function of waveguide parameters and slit half width are derived respectively. Relation between beam parameters and slit half width are investigated by numerical calculation. The results show that beam parameters vary with changing slit half width, and if the optical field distribution in the cladding layers is not taken into account, beam propagation factor will be less than unity.

It is found that both the completely unpolarized stochastic electromagnetic beams and completely polarized stochastic electromagnetic beams will keep their spectral degree of polarization or become partially polarized under different constraint conditions during their propagation in free space. It is shown that it depends on δ denoting the variance of the correlations between the components of the field and σ denoting the variance of the intensity distribution across the source.

Real-time imaging is one important development direction of THz imaging technology. In this paper, utilizing CO2-pumped THz laser made by Coherent Inc. and 124 ×124 array detector, imaging experiments on RMB watermark are made and the experimental results are studied. In the experiments the frequency of the laser is 2.5 THz. The method of image averaging could realize the improvement of the image signal-to-noise ratio and the extraction of the watermark image is achieved by the method of the threshold segmentation. The real-time clear images of RMB watermark have been obtained from this imaging device and the image processing methods used could make the watermark clear. The experimental results show that this imaging mode has enormous advantage of improving image resolution and imaging frame.

The effects of source cross polarization on the polarization degree of radiation beam were investigated. Formulas expressing the spectral degrees of coherence, of polarization and the degree of cross polarization of a Gaussian-Schell-model source were analytically derived. From these formulas it was demonstrated that sources with the same set of degrees of coherence and polarization may have different degrees of cross polarization. The spectral degrees of polarization as a function of the distance from the source were calculated for coherent and incoherent sources respectively. The plots show that the correlation coefficients between the two mutually orthogonal components of sources may evidently affect the longitudinal evolution and the asymptotic values of the polarization degree.

With the development of digital image processing, the abuse of tampered images often appear in domains of news and judicial and did great harm. This paper analyzes the usual photomontage detecting methods, such as higher order statistics analysis, camera response function analysis, direct torgue control (DCT) coefficient analysis and etc. All the methods’ applicable condition and limits have been discussed. This paper also gives the prospect of this domain’s research.

During the process of digitized duplication, in order to reproduce and reappear the color of the color image manuscript, a closed-loop color correction method with the application object of color image duplication system, composed of a scanner and a color ink-jet printer is proposed, which is based on the colorimetric characterization theory and applies the model of polynomial regression. Compound and unitied calibration is achieve by correcting tristimulus values of image pictures when it is being scanned and printed. Accuracy of color restoration is improved effectively by circulating approximation. Theoretical analysis and experimental results show that after color correction by the method, the maximum color difference between the final copy and the original copy is reduced from 48.51ΔE*ab to 7.90ΔE*ab, and the average color difference is reduced from 15.91ΔE*ab to 2.69ΔE*ab. Thus it achieves accurate reproduction and reappearance of color.

The method of image processing of terahertz time-domain spectral imaging in the time-domain and frequency-domain is discussed. Compared to other intensity imaging, terahertz time-domain spectral imaging technology has an obvious advantage that it has a large amount of information. According to different requirements, different image characteristics are demonstrated by selecting different physical parameters in order to provide more accurate sample information. Each pixel corresponds to a time-domain waveform so that any amplitude or phase data point from the time-domain signal or its Fourier transform spectrum can be used to make graphs to remodel the space density distribution, the refractive index and the thickness distribution of samples. It is worth mentioning that, in the frequency-domain model, graphs can be made by different parameters at each frequency, such as amplitude, absorption, refractive index, energy, power and so on, which can be used to investigate the terahertz multi-spectral imaging technology. The results of these researches have important significance to improve the resolution of THz imaging and THz image recognition technology.

Utrasonic burst phase thermography technology used the ultrasonic as heat source to heat the material , if there are some defects(crack or delaminition) in the sample, the ultrasonic energy will cause the fiction or thermal elastic effect of the place where the defects is. At the meantime, an infrared camera controlled by the computer are used to detect the thermal wave sequences and collect the information. Then processing the original thermal sequence by Fourier transforrmation, the amplitude and phase information of the defects in the material are obtained. In this paper, two laser welded seams which are welded by different laser powers and a wheel of an electronic motor saw were detected by this method, and the amplitude and phase information was shown as images.

Because of cloud or smoke in remote sensing images, the information of earth objects could not been read. The models of attenuation light and airlight had been analyzed. The advanced Retinex algorithm has been applied to remove cloud or smoke from the remote sensing images. The result shows that the advanced single-scale Retinex algorithm with small standard deviation of Guassian function in convolution kernel (SSRS) was effective for removing cloud or smoke. The cloud or smoke was in brighter region in the remote sensing images. In particular, the advanced Retinex algorithm SSRS was more effective for removing the thick cloud or smoke. The advanced Retinex algorithm SSRS had three steps. First, the complementary image of original image could be got and the brighter region could be reversed into darker region. Second, the advanced Retinex algorithm SSRS had been applied to enhance the darker region. Third, the complementary image could be got and the information of brighter region in original images had been enhanced.

Because of cloud in remote sensing images, the information of earth objects could not been read. A new method for removing cloud had been projected based on wavelet analysis. Because of the cloud in remote sensing images was in the part of low frequency, the new method enhanced the sence information by various approximation coefficients and detail coefficients with various weight after wavelet transform. The criterions of entropy and fidelity had been applied to evaluate the quality of removed cloud images. The result shown the cloud in remote sensing images was removed by wavelet transform. First, the effect of removal cloud was good when the detail coefficients were multiplied weight and the information of sence was enhanced for decomposition order over 6. Second, the fidelty of the good enhanced images was 0.87±0.03 and 0.89±0.04 for thick cloud and for thin cloud, respectively. Finally, the color could be restored for removal cloud images by Brovery transform. In particular, Brovery transform was suit for removal thin cloud in remote sensing images.

Nowadays, many kinds of factors related with illumination in the gathering process of iris recognition system bring light spots to the iris images, and the light spots lead to the loss of the iris texture. To a great extent, it affects the precision of the iris recognition system. In order to improve the accuracy and practicality of iris recognition system, an iris recognition method based on eliminating disturbance points in iris image is proposed. This method uses the image fusion technology to match two images of the identical iris which have light spots in different positions. As a result, the light spots are effectively eliminated after the image fusion. Then it uses an iris block-encoding method based on statistic of local information for feature extraction and encoding. After that it calculates the Hamming distance between different iris codes and obtains the recognition results according to Hamming distance. When the Hamming distance threshold equals to 0.255, the accuracy of iris recognition is 99.74%. The experimental results demonstrate that this method can effectively eliminate the disturbance points and has high accuracy, which can meet the demands of iris recognition.

Under the one-dimensional tight-binding miniband and contact interaction approximation, the extended semiconductor Bloch equation is employed to investigate the optical absorption spectra and evolution of the polarization wavepacket in semiconductor superlattices driven by a terahertz field, after the excitation by a femtosecond laser pulse. Under a direct current (DC) bias, the optical absorption spectrum changes from the absorption band in the case of zero field into a series of equal-distant peaks, so-called Wannier-Stark ladder, with the energy distance being proportional to the field strength. The Wannier-Stark ladder is the counterpart (in the frequency domain) of the periodic oscillation of electrons and holes in real space and in momentum space, i.e. Bloch oscillation. Under a THz alternating current (AC) field, the absorption spectrum also consists of a series of peaks, called dynamical Stark ladder, however, the energy distance is equal to the photon energy of the applied THz field and is independent on the field strength. Furthermore, the absorption edge is shifted. When a DC field and a THz field present simultaneously, the absorption edge does not shift, and the spectrum becomes richer. But the complicated features can be interpreted and identified by the combination of the Wannier-Stark ladder and the dynamical Stark ladder. The ratio of the Bloch frequency to the frequency of THz field and the ratio of field strength of the THz field to the frequency of THz field are two determinant quantities. If the ratio of the Bloch frequency to the frequency of THz field is an integer n, then n-order harmonic wave of THz photon is generated in one Bloch frequency. If the ratio of the Bloch frequency to the frequency of THz field is a fraction, then dynamical fractional Stark ladder is formed. On the contrary to this, the ratio of field strength of the THz field to the frequency of THz field determines the spatial extension of the polarization wavepacket.

With the development of technology, optical-experiment simulations, as a novel alternative method different from theory and experiment to explore new things, are attracting more and more attention from both scientists and teachers. There are two methods for Matlab program of the Fresnel and Fraunhofer diffraction patterns, one is diffraction integration, and the other is Fourier transform. In this paper, Fourier transformation well combined optical experiment phenomena and Matlab program. And with a lot of comparison of simulation experiments optical diffractive law was verified, which will contribute positive effect to optics teaching.

The micro-nano sized waveguides are the basic building blocks for on-chip interconnects, and their basic function is to transmit light with low loss. The propagation loss is one of the indexes to evaluate the fabrication quality and performance of micro-nano sized waveguides. With cross section size one or two orders smaller than that of conventional waveguides, and due to the large uncertainty and the difficulty of light coupling, the propagation loss measurement is comparatively difficult to perform. This paper discussed several propagation loss measurement methods suitable for micro-nano sized waveguides, including cut-back method, Fabry-Pérot cavity interference fringe contrast ratio method, and Fourier transform method, etc. The analysis and comparison on the above mentioned methods in terms of measurement accuracy and applicability was given, that is, the cut-back method is liable to the uncertainty of light coupling with comparatively large error, the Fabry-Pérot cavity interference fringe contrast ratio method is immune to the uncertainty of light coupling, but only applicable to the case of single F-P cavity, the Fourier transform method is not only immune to the uncertainty of light coupling, but also applicable to the case of multi-cavity.

The methods to evaluate image quality based on the radial fuzzy degree function and structural information of images respectively to evaluate the degradation degree of radiant blurred images result in the high speed forward motion between the camera and the target, are studied. The conclusion that it is unstable to describe the fuzzy degree of images with different prospect quantitatively by radial fuzzy degree function, is got. According to imaging mechanism of radiant blurred images and human visual characteristics. The method based on structural information of images put forward, which can evaluate restored images’ quality of radiant blurred images,without the clear image; Using it, when the normalized iterative method is used to restore radiant blurred images, its excellent fault tolerance ability and good feasibility in practical engineering application are exhibited.

The full-vector finite element method is applied to investigate the property of a photonic crystal waveguide coupler consisting of a square lattice of dielectric cylinders in air. The coupling ratio with different coupling lengths, wavelengths and refractive indexes are given. The simulation results show that the photonic crystal waveguide coupler (PCWC) can be widely used as switches, multiplexers and demultiplexers by changing certain structure parameters and coupling ratio.

Defect modes are found inside the photonic gap with zero effective phase when mutiple periodic double defect layers of single-negative materials are added into the traditional one-dimensional photonic crystals. The results show that by varying the total thickness of the defect layers, the frequency interval of the defect modes is increased and the transmission of defect modes is decresed when the thickness of each defect layer is identical. When altering the thickness-proportion of the defect layers the frequency interval of the defect modes can be changed. If the general zero average permeability and permittivity conditions are both satisfied, twin defect modes are found to merge into each other. On the other hand, defect modes inside the zero-effective-phase gap are insensitive to incident angle. However a new angle gap emerges because of the change of the incident angle. The angle gap enlarges with the increasing of the incident angle but is unrelated with the thickness of the defect layers.

This paper introduces the extend caliber and collimate method, which receive the centralized axis to a appropriate caliber in collimator on many spectra. The discrete axes which are far from the center are guided to the collimator by the special design arm, extend arm can rotate and slide along the auto-collimator so that different position targets could be required. The parallel precisions between the extended axis and the original axis of collimator affect the testing precision of the which system. The extended arm programs and high precision auto-erecting are given, which not only make the problem easy, but also ensure the precision. In practice the accuracy is better than 0.01 mrad.

Self-assembled InAs quantum dots (QDs) overgrown by different strain reducing layer have been prepared on GaAs substrate by molecular beam epitaxy (MBE). Photoluminescence (PL) measurements shows that PL intensity is enhanced by InxGa1-xAs cap layer, which may be attributed by reducing strain and defect among the QDs. However, the larger x (x≥0.3) may result in a lower material quality of excessive relaxation and generating an interface potential barrier near QDs. It has been found that the carriers may migrate between GaAs barrier and InAs QDs, while the interface potential barrier retards the migration. It has been found that the PL decay spectra of InAs QDs with a low-In-component InGaAs or AlAs cay layer follow the second exponential decay process. Time-resolved PL measurements were also used to analyze the special PL decay of InAs QDs with different strain reducing layer.

Lanthanum-substituted bismuth titanate (BLT) thin films were deposited on fused silica substrates by chemical solution deposition method. The crystallinity of BLT was examined by X-ray diffraction. The optical properties of the BLT thin films have been investigated by optical transmission spectra and spectroscopic ellipsometry. The refractive index n and the extinction coefficient k of the BLT thin films were obtained. The birenfrigent shift as a function of applied voltage of BLT thin films on fused silica was measured. The BLT samples showed a quadratic response and quadratic electro-optic coefficient R=1.48×10-18 (m/V)2 was gotten at He-Ne laser632.8 nm.

This paper describes super-continuum generation of femtosecond lasers(800 nm, 1kHz, peak intensity 1012 W/cm2) with PMMA polymers.The white light filaments changed from super continuum to pumped light spectrum is founded , the circle structures of the variable spectrum are recorded. The effect of interaction time on the filaments is presented.The relationship between the damage threshold of the PMMA and interaction time is investigated,The experimental results show that PMMA has the photorefractive properties in the field of super-continuum generation.

Ce3+∶YAG single-crystal optical fiber fluorescent materials for LED white light sources have been grown directly from powder source rod by laser heated pedestal growth method. Various diameters Ce3+∶YAG single crystal optical fibers from 150 μm to 1000 μm are available by single-step and/or multi-step process. Fluorescence spectrum of the grown optical fiber materials under 465 nm LED pumping is measured and results show strong wide band fluorescence emission near 550 nm wavelength. High efficient LED white light sources can be got by combining blue LED and grown Ce3+∶YAG single-crystal optical fiber. The developed optical fiber white light sources show good white light quality with the 5881 K of the color temperature and the CIE color coordinates (x＝0.310, y＝0.350) and 75 of the CRI. Combined with the good qualities of optical crystal materials and optical waveguide properties, the grown Ce3+∶YAG single-crystal optical fibers have a high efficiency of LED pump and fluorescence collection prior to general powder Ce3+∶YAG fluorescent materials. It can be used for high power LED white light sources in future.

The 0.1%～3.0% Er3+-doped TiO2 nanocrystals have been prepared by sol-gel method in which titanium etrachloride was adopted as the precursor. The phase structure, composition and phonon cutoff energy of Er3+-doped TiO2 nanocrystals were characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectra and Raman spectra. The nanocrystalline size of TiO2 is reduced with increasing Er3+ concentration. The intense green and red emissions around 525 nm, 548 nm and 660 nm corresponding to the 2H11/2→4I15/2,4S3/2→4I15/2 and 4F9/2→4I15/2 transition of Er3+ ions were observed under excitation by 980 nm. The relations among Er3+ concentration, the heat treatment temperature, laser power and upconverted emissions were studied. The result indicated that in the sample, when the Er3+ concentration is 0.5%, the heat treatment temperature is 800 ℃, the upconversion luminous efficiency is highest .The upconversion mechanisms of Er3+-doped TiO2 nanocrystals were also discussed.

Germanium and silicon monoxide are two kinds of optical thin film materials used frequently in medium-wave infrared band. Study on their optical properties is the key to design and fabricate medium-band thin film. Germanium and silicon monoxide are selected as high and low refractive index materials respectively and the substrate is synthetic sapphire. Triple cavity band-pass filter of which the center wavelength is 3.5 μm, relative bandwidth is 4.8%, and transmittance of pass-band is about 80%, was designed and fabricated. Spectrum measurement and environment reliability experiment show that the infrared band-pass filter is competent for engineering application.

The pursuit of efficient and highly target-selective transporters is an active topic in cancer targeting therapy. A novel cancer-targeting probe based on integrin αvβ3 monoclonal antibody labeled carbon nanotubes was developed to investigate cancer cell targeting in vitro. The results revealed that the system had a high efficiency in cancer cell targeting in integrin αvβ3 positive U87MG cells but low targeting in HUVEC cells, indicating that the high efficiency was due to the specific targeting property of integrin αvβ3 monoclonal antibody. Thus, the integrin αvβ3 monoclonal antibody labeled single-walled carbon nanotube (SWNT) probe is a potential carrier-candidate for cancer-imaging and drug-delivering in cancer therapy.

Magneto-optical crystal YFeO3 has been grown by optical floating zone method. Some key issues on crystal growth, such as feed rod, growth rate and annealing process, have been discussed. It was found that the stability of the melt was seriously affected by the diameter, the density and the homogeneity of the feed rod. The dense and uniform feed rods with pure phase were prepared by complete mixing and repeated sintering at a suitable temperature. YFeO3 crystal up to Φ10 mm × 40 mm was obtained by the optimizing growth conditions: the diameter of the rod was less than 10 mm, the growth rate was about 3～5 mm/h, and the furnace was slowly cooled down after the growth finished. The refractive indices and extinction coefficients of YFeO3 crystal were measured by means of ellipsometric spectroscopy. YFeO3 crystal shows high refractive indices.

The Yb3+/ Er3+ co-doped and Er3+ single doped oxyfluoride glasses were prepared by high temperature melting method. The optical properties of the samples were studied. According to differential thermal analysis (DTA) curve, the samples were thermal treated at 552 ℃, and micro-crystalline were formed after thermal treatment. The near infrared luminescence spectra under 980 nm excitation of the samples were recorded at room temperature. The results showed that the near infrared luminescence intensity increased with increasing Yb3+ concentration. This is because Yb3+ ions absorbed pumped energy of 980 nm through 2F7/2→2F5/2 transition, and then the energy was transferred to Er3+ ions by the way of resonance energy transfer and enhanced the 4I15/2→4I11/2 transition.

By using the transfer matrix method, the defect modes of one-dimensional photonic crystals composed of single-negative materials are investigated. The transmission peaks in band gaps shift to the low-frequency side with the increase of the layer thickness of the air defect layer, which accords with the properties of the photonic crystals composed of traditional positive materials. However, the position of the peak is found to be insensitive to the incident angle as well as polarization of the incident light, which implies the formation of the peak cannot be contributed to the Bragg effect, but the phase elimination effect. The results show that the structure is different from the structures composed of pure positive or negative materials. These properties of the structure show the potential application of omnidirectional tunable photonic filters.

The treatment of growth solution is of great importance to KDP and DKDP crystals. Two kind of solution treating methods are studied in this paper: the organic addictive CS doping in KDP solution and the continuous filtration of the solutions during DKDP crystals growth. The optical transmission spectra for different sectors in crystals, scattering distribution at boundary zone between prismatic and pyramidal sectors and laser damage threshold of crystals are determined for comparison. The results show that moderate dopant concentration of CS would improve the optical quality of KDP crystals: less amount of impurities, higher transmission at ultraviolet band, reduction in evidence of inclusions or cracks inside. In crystal gown with continuous filtration which eliminates effectively the unsolvable particles in the solution, low dislocation density is found distinctly and laser damage performance is improved.

Using first-principles calculations with the generalized gradient approximation (GGA), the band structure of the new BxGa1-xSb ternary alloys is studied theoretically, and the impact of the born incorporation on the band structure of BxGa1-xSb is also investigated. The result shows that, when boron relative mole content is between 0 and 18.75%, the value of Γ1c-Γ15v band-gap energy is increasing monotonously by ～17.5 meV/%B with a small band-gap bowing parameter (2.23 eV), while the value of X1c-Γ15v band-gap energy is decreasing monotonously by ～12.8 meV/%B. When boron content x is below 10%, BxGa1-xSb is a direct band-gap alloy. In addition, the formation enthalpies of BxGa1-xSb alloys with born relative mole content at 6.25%, 12.5% and 18.75% are also calculated, respectively. The comparison between the calculated formation enthalpies of BxGa1-xAs and that of BxGa1-xSb indicates that the content of boron in BxGa1-xSb may be able to reach 7% relative mole.

The change of circuit parameter caused by variable temperature is an important element that affects the accuracy of photoelectrical encoder. The mechanical deformation of encoder the characteristics of infrared-LED and temperature characteristics of recieving detector will vary with the change of ambient temperature. This variation will change the amplitude of the encoder’s output signal and bring measurement errors, especially for amplitude breakdown high-precision encoder. A method of temperutre compensation is proposed, which can automatically compensate the variation caused by the variable temperature and stabilize the amplitude of output signal in a wide temperature range about -40 ℃～+80 ℃. Experimental results show that the amplitude signal change of a 21-bit encoder at 65 ℃ is 20%, and the amplitude signal change is 3% after adding temperature compensation.

The transmission spectrum of Sagnac comb-like filter based on high-birefringence polarization maintaining fiber (PMF) and Sagnac fiber loop mirror can be tuned easily. A novel switchable wavelength erbium-doped fiber ring laser by using this filter is proposed. By adjusting two polarization controllers (PCs) within filter properly, a single-, dual-, triple-, quadruple-wavelength laser beam can be obtained at room temperature in experiment. The principle of stable operation at room temperature is based on inhomogeneous broadening effect induced by a deeply saturated effect in the erbium-doped fiber. The wavelength interval is 1 nm, which can be optimized by using proper PMF length.

Incremental photoelectric encoder usually adopts zero position graring providing absolute zero position in order to prevent from data fault during power failure suddenly. Based on theory of generating index pulse, a mathematical model is established. Combining with some objective requirements in the practical applications, the optimal zero-position reticle series is obtained and its luminous flux ratio curve is simulated by using VB language to program with threshold method, which offers a principle and a new realizing approach to design zero-position grating, especially more lines. At the same time, we provide the inversion program in order to give the luminous flux curve of measuring zero-position grating or when it is intercepted or changed, which brings the advantage in measuring zero-position grating. In order to check the feasibility of the method, some examples are given, which prove the zero position reticle serics which fulfills the demands of incremental photoelectric encoder for zero position grating having many advantages such as the maximum residual voltage being lower, peak value voltage being higher. This explains that the method of generating or measuring zero-position grating has many advantages such as reducing operation quantity, lessening degree of programming complexity comparing with enumerating method, and the method also ensures that the zero-position grating has the properties of large luminous flux and high contrast.

The infrared focal plane arrays (IRFPAs) technology has been driven to the third generation. Readout integrated circuit (ROIC) is an important subassembly of focal plane arrays. To reach the ideal working state, ROIC needs to be supplied with clock drive impulse and setup voltage. IRFPAs driving circuit using atme189s51 singlechip has been designed, which has facility performance, powerful drive ability. While the out-put voltages are high and low, the output driving currents are 4 mA and 28 mA separately. It can be used to drive 128×1 IRFPAs. Via brief modification in program, driving circuit can adjust clock drive impulse frequency、integration time and readout time etc, which can be used to drive 256×1 IRFPAs.

Temperature baking is one of the common methods of accelerating test. Vacuum baking experiment of HgCdTe short-wave infrared (SWIR) detectors at the room temperature was studied. The samples were divided into four groups, baking temperatures were 60 ℃, 70 ℃, 80 ℃ and 90 ℃, respectively. The R-V characteristics of the detectors at different baking temperature were analyzed. Results show that baking experiment causes the increase of series resistance, the decrease of tunneling current, and the increase of generation-recombination current mechanism according to the effect of temperatures on R-V curves. The increase of detectors contact resistance is caused by long time baking. On the other hand, the appropriate baking temperature can reduce the inner defect energy of the devices and reduce the effect of indirect tunneling current. Results also show that high temperature baking may damage the passivation layer and reduce the generation-recombination carrier lifetime.

Readout integrated circuit (Roic) should be applied with clock work pulses which are usually generated by signal generator, discrete component, MCU and complex programmable logic device (CPLD). In this paper, a method of designing clock work pulses with CPLD for linear infrared focal plane array (FPA) capacitance trans-impedance amplifier (CTIA) readout integrated circuit is presented. Experimental results show that this circuit can be capable of driving FPA steadily after overshoot of work pulse is eliminated by increasing series-resistance at the output terminal. This portable circuit with small volume can be used for FPA’s reliability test. Comparision result of experimental value and design value shows that this circuit is not suitable for parameter measurement because of low resolution compared with high-precision signal generator.

The accurate color characterization of displays is the basis of the color management. The characterization of the liquid crystal display (LCD) is difficult because of the variant primary chromaticity and primary crosstalk. The gain-offset-Gamma (GOG), Two-trimary crosstalk (TPC) and piecewise partition (PP) were employed to study on the experiments of color characterization of the same LCD. The characterization accuracy were evaluated with the CIEDE2000 color-difference formula. The experimental results show that the performance of the models were quite different. The mean color difference of the PP model reaches 1.2660 CIEDE2000, while the GOG model is 3.9849 CIEDE2000, and the TPC model is 5.8779 CIEDE2000. The GOG and TPC models can satisfy the general needs and the PP model can be used in the higher requisition color reproduction.

The acousto-optic tunable filter (AOTF) is one kind of prismatic elements which is developed by the abnormal acousto-optic interaction principle, it has wide applications in many fields. The spectral resolution is one of the key index for evaluating the performance of the acousto-optic tunable filter. We have analyzed the factors that were connected with the spectral resolution. And we have pointed out that the improvement of the spectral resolution was limited through optimizing the design parameters of a single AOTF. A new method called “double filtering” that can effectively enhance the spectral resolution is presented. The principle of double filtering method is described. The main technology of improving the spectral resolution by double filtering method is discussed. The feasibility and the advantage of this method on the spectral resolution improvement are confirmed. The double filtering method provides a new idea for the improvement of the spectral resolution.

Based on analysis the high power solid-state laser facility’s optical system, the double lenses were design which fitted the reqirement. The tolerance of double lenses were given through tolerance analysis. These conclusions provide guidance to use double lens in the high power solid laser facility. The application of double lens in the facility is meanful to reduce the building cost and improve the stablity of facility.

Uncooled infrared focal plane array (IR-FPA) assembly is power device. The temperature of uncooled IR-FPA assembly will be risen up along with working time, which directly affect the performance stability of the uncooled IR-FPA assembly. A design based on propertional integral (PI) control which is composed of thermo-electric cooler (TEC), PI controller, Pt-100 temperature sensor is capable of measuring and controlling temperature, and the temperature controlling circuit can keep the temperature change of the uncooled IR-FPA detector between 25 ℃～15 ℃. The precision of controlling is±0.1 ℃, so that the temperature controlling system based on PI control can ensure the uncooled focal plane array detector work in the temperature of high stabilization and precision without noise in addition.

According to requirement of the actual laser system, a design scheme of a continuous phase plate (CPP) for laser beam with random phase distribution has been developed. A kind of method has been established to analyze the smoothing character of CPP. The random theory is employed to study the statistic characteristics of the laser beam. The propagation parameters have been calculated and the results show the far-field distribution of the laser beam. Using the design principle, a CPP that can be used in the actual light path is designed and its surface character is analyzed in detail.

Based on the finite volume modular, the coefficient of convective heat transfer is studied, when plasma electrodes Pockels′ cell is operated at conventional pulse mode. Considering requirement of thermodynamics, the discharge cavity is redesigned to enhance convective heat transfer. The results indicate: at conventional mode, the coefficient of convective heat transfer is too small, 1.01 W/(m2·K), because of low operation pressure, low pumping speed, no considering of thermodynamics requirement. By pushing the pumping speed, increasing operating pressure, augmenting pipe diameter, and redesigning arrangement of inlets and outlets, coefficient of convective heat transfer is enhanced prominently, which reaches to 8.02 W/(m2·K).

The fabrication process of InGaAs mesa detectors contains the ohmic contacts of n-InP and the stretched electrode with good reliability. Cr/Au as the contact material for the n-InP is reported. The transmission line method (TLM) is employed to research the ohmic contacts at different annealing condition and Auger energy spectra (AES) is employed to research interface between Cr/Au and n-InP at different annealing condition. The results show that the good ohmic contacts are obtained without annealing treatment, while the ohmic contacts are degraded after annealing. The presence of Cr2O3 in the Cr layer deposited with ion beam sputter causes oxygen out-diffusion into the Au layer at annealing condition. The fabrication process of InGaAs mesa detectors is simplified by using the unannealing Cr/Au as the ohmic contacts of n-InP and stretched electrode.

The dark currents of near-infrared InGaAs detectors were studied by I-V curves, the relations between the dark currents of InGaAs detectors and the dark signals of InGaAs FPA were analyzed. The result shows that the dark current is dominated by diffusion current at -100 mV reverse bias down to about 273 K, the dark current is dominated by generation-recombination current at -400 mV reverse bias down to about 273 K, the effect of interface current on the dark current increase at the smaller bias voltage.The dark currents of InGaAs linear detectors is the major reason of the dark signal output of InGaAs FPA, the smallest dark current among InGaAs linear detectors is about 0.92 pA at -3 mV reverse bias, which cause the corresponding electrons of 2.87×105 in FPA and the corresponding dynamic range of 56 dB. Pixel-to-pixel variations of CTIA in ROIC result in variation of the actual bias voltages applied to the diodes which increase non-uniformity of the dark signal output of InGaAs FPA. The result shows that the further decrease of the dark current of InGaAs detectors is an improvet approach to improving the dynamic range of InGaAs FPA.

Major factors that influence the performance parameters of high-speed charge coupled device (CCD), such as CCD’s frequency response characteristics, grounding return, electromagnetic interference, image cross talk et al., were analyzed and considerated. A high-speed CCD sensor with 400 pixel×400 pixel was designed, fabricated and tested. The analysis shows that the CCD sensor has good performances and features such as good responsibility, high dynamic range and low noise et al., It was greatly improved for the multi-tapped high-speed CCD sensor to optimize its uniformity among multi-tapped outputs and to reduce its noise and signal cross talk, which shows that the design and layout used are reasonable and efficient.

The mechanics of the potential well of buried channel charge coupled device (CCD) are described. By solving Poisson’s differential equations, a brief calculation of the optimum operating point and maximum charge capacity has been given. The effect factors such as the buried channel junction depth and substrate doping concentration on the CCD’s optimum operating point and maximum charge capacity are analysed. According to the theoretical calculation, the charge capacity of the 6000 pixel linear CCD designed by our group is 4643 e/μm2.

Multifocal intraocular lenses which mainly include diffractive type and refractive type can provide patients with good vision in varius distances. But they also result in image quality reducing. This article suggest a new design method of aspherical intraocular lens. In this method, when pupil is lager, the dominant eye will keep a better vision of far distance, at the same time, get vision of near distance; or make the undominant eye keep a better vision of near distance and get vision of far distance. When two eyes observe objects of different distance, good binocular vision will always be gained and the visual ability of both eyes will not be influenced. We will also report the ZEMAX raytracing results on model eyes which consist of aspherical cornea and nature lens, and the optimized results based on the balance of binocular vision.

A model eye with aspherical cornea and nature lens are used to be calculated by raytracing method (ZEMAX program). The calculation shows that, spherical aberration is a key factor to influence the image quality of the human eye. To the emmetropia eyes, the negative spherical aberration of nature lens can compensate the plus spherical aberration of the cornea to reduce the whole spherical aberration of the human eye and keep a better vision. But the aged nature lens has little compensation with the spherical aberration. In order to reduce spherical aberration, the intraocular lens is needed to be aspherical. For a give Q value, the influence on the spherical aberration is proportional to the surface power. To minimize the spherical aberration of the whole eye, negative Q is needed in intraocular lens.

Deformable mirror (DM) is a main device in adaptive optical systems, which is widely used in wavefront correction of human eye. Micromachined membrane deformable mirror (MMDM)and piezoelectric deformable mirror (PDM) are two types of DM, and they perform differently in adaptive optical system because of their different structure. In this article, a 59-channel MMDM and a 37-channel PDM are compared. Zernike generations of common aberrations (including astigmatism, coma, trefoil and spherical aberration) are observed in a close-loop system. It shows that the results are more effective when the target value is smaller.

With the use of large-mode-area (LMA) double clad fiber, output powers of a single fiber laser increase dramatically. However, it makes the laser operate with high-order modes and the beam quality degrades at the same time. In this paper, fiber tapering is introduced to control high order modes of a LMA fiber laser, which has a 43 μm core with 0.08 NA. And a 20 mm length tapered zone is employed, 10 mm in front of the output end. And the minimum of the core diameter of the tapered zone is 9 μm. When the launched pump power is 119.1 W, 56.4 W single mode output can be obtained. On the basis of the experiment, thermodynamic characteristics of the tapered fiber laser are calculated theoretically. The experimental results are in agreement with the calculated results. And it offers a reference for achieving higher single mode fiber laser and its cooling scheme.

The paper mainly discusses the design of a simplified operating lamp structure——an increase color temperature reflector with wide incident angle. We analyze the spectrum requirement on surgery light by using vertical triangular interpolation calculate color temperature and Tristimulus calculate color-rendering Index. And by comparing one result of an ordinary thin film, we optimized the design of on the film and shape of the reflector and designed a new color temperature reflector with wide incident angle. And the color rendition of the new design is even better when the incident angle changes in a wide range.As a result, the design of thin film decreases the complexity of the surgery light structure and enhanced the applying efficiency for the light which can be used as a replacement of traditional operating lamp structure.

A multiwavelength fiber laser with symmetrical nonlinear optical loop mirror, from which up to 8 wavelengths can be generated, has been proposed and demonstrated. The intensity-dependent transmission of nonlinear optical loop mirror due to nonlinear polarization rotation effect is used to alleviate the mode competition in the homogeneous broadening gain medium of erbium-doped fiber. Besides, a novel comb-like filter i.e. birefringence fiber filter is proposed and utilized, which has in-line configuration. At the same time, the effect of the 980 nm pump power on the multiwavelength generation has be investigated. It is shown that the pump power contribute a lot to the evenness of the multiwavelength spectra.

The modulation transfer function (MTF) is one of the fundamental parameters to evaluate the infrared optical lens. In this paper, the knife-edge scanning method is put forward to evaluate the MTF of infrared optical lens. Then measure the MTF of a infrared lens with f=50 mm, F=1.2 and wavelength=8～12 μm.And MTF is got at several characteristic frequencies. At last the curve of MTF is presented.