Based on reasonable designing,precise temperature controlling of the Cr4+∶YAG,Nd∶GdVO4 and LD,passively Q-switched infrared laser was obtained with average output power of 70 mW,pulse duration of 22 ns,repetition rate of 14 kHz,and peak power of 230 W. Then by a piece of type-Ⅱ critical phase matching KTP crystal for extra-cavity and for the system of telescope second-harmonic generation,green laser at 532 nm was achieved with average power of 28.8 mW,pulse duration of 19ns,and peak power of 108 W. The effect of small beam radium was also discussed.

In order to improve the noise-reducing ability of light source,a hybrid controller using fuzzy control and proportional control simultaneously is proposed,which provides a high precise control on the output power of a laser diode with the center wavelength at 650 nm. Under the Fuzzy-P control,the experimental results show that the static stability of output power of a laser diode reache±0.48‰;and the dynamic stability is superior to±1‰.

Lock-in characteristic of four-mirror ring laser gyro was studied both by theory and experiments. The relationship between cavity overall back-scatter with the back-scatter of the mirrors and distance between mirrors was given. The cavity overall back-scatter was of two wave length period in cavity length. The results of two experiments are validated this relationship.

Using Bathe model,the ionization and explosion process of argon clusters in intense femtosecond laser pulses(100 fs,1016 W/cm2) has been studied. The results show that the average energy of argonions is proportional to the square of initial radius of the cluster for small clusters,and the explosion mechanism is typical Coulomb explosion. With increasing cluster size,the average energy of argon ions increases slowly and gets saturated gradually beyond a critical cluster size. The simulation results are in good agreement with experimental results.

High performance parallel computing platforms are built by interconnecting a group of PCs. The parallelized 3D FDTD code is achieved and is useful for the studies of the transmission properties of photonic crystal slab W3 waveguide. The analysis of the performance of parallel environment indicates that for a large-scale computation problem,the parallel FDTD algorithm can achieve a better fixed speedup. Transmission spectrum and field distribution of a photonic crystal slab W3 waveguide are calculated with the use of the presented technique,and the obtained results show that photonic crystal slab W3 waveguide can control the propagation of light in the three directions and there is mini-gap for the guides.

Considering the refractive index change of bending fiber relative to straight fiber due to internal stress of bending fiber,bending loss model of mono-mode fiber was modified. On the basis of modification,the three results were compared,i. e.,experimental data obtained by other authors,corrected and uncorrected theoretical results. The result shows that the corrected results accord with experimental data well. It will provide as an important reference for analyzing transmission characteristics of light in strong bending mono-mode fibers.

A novel spatial light modulator called reflector moving grating light modulator is proposed. Each pixel mostly consists of a fixed grating and a movable reflector. The optical performance of this modulator is a key parameter,so it is necessary to analyze the optical performance. With scalar diffraction theory,its optical performance is analyzed in details. Meanwhile,computer simulation is carried on,and the influence of several key parameters on the diffraction efficiency and contrast ratio is presented. All these results indicate that the height between the fixed grating and movable reflector must be controlled at λ0 in off state,5λ0/4 in on state respectively,and the occupation ratio of the fixed grating has an important influence on the optical performance whose optimized value is 0.5.The contrast ratio at different wavelength width is given out,wider wavelength,worse contrast ratio.

The rigorous nonorthogonal vectorial coupled-mode theory is presented for the isotropic waveguide with isotropic disturbances,based on the Maxwell Equation. The coupling term due to polarization,which is presented in the scalar coupled-mode theory with the vector correction of the Wei-Ping Huang,isn't included in this rigorous vectorial coupled-mode theory,and the term is emerged during the derivation. It is because that the coupling term due to polarization and the ignored term due to the weakly guiding approximation are as small as the second order,and they are just the same. Therefore,the rigorous vectorial coupled-mode theory has not the coupling term due to polarization which can be looked as the vector correction for the scalar coupled-mode theory.

The theoretical analysis based on three Markovian stochastic models provides a closed-form solution for the difference-frequency Rayleigh-enhanced polarization beats. The subtle Markovian field correlation effects have been investigated. The different roles of the amplitude fluctuations and the phase fluctuations have been pointed out both in time-and frequency-domains. The difference-frequency REPB signal shows symmetric temporal behavior,and differences among three Markovian stochastic fields are quite sensitive to the change of bandwidth,and as the bandwidth increases,the difference becomes obscure.

The impact of XPM effect on the pulse transmission in the NOLM switch with high working speed in the single wavelength channel and WDM 4-wavelength channel is analyzed by the split-step Fourier method based on the coupled nonlinear Schrodinger equation. The simulation results show that XPM induces the crosstalk and aberration of signals and deteriorates the switching performance of NOLM. Furthermore,the impact of XPM crosstalk of wavelengths of the pulse is far more than that of XPM effect of counterpropagating pulses in the fiber loop in the WDM system. The shorter the wavelength is,the lower the output power of NOLM is. The pulse pedestal and walk-off effect induced by XPM in the middle wavelength channels are more than those in the edge wavelength channels.

The mechanical transfer characteristics of single mode quartz fiber optic sensor with double coating is studied. The theoretical model of linear elasticity between quartz fiber optic with double polymer cladding coating and buffer are presented. The theoretical results demonstrates that the mechanical transfer characteristics of double coating depend on the relative magnitude of elastic modulus between cladding and buffer under the small radius approximation compared with the model of single coating. When the elastic modulus of buffer is much bigger than that of cladding,its action can be neglected. In the experiment,the experimental study on the average transfer coefficient of different scale fiber optic sensors embedded in the matrix material has been carried out based on white light interference method and the result of experiment accords well with that of theory.

The effects of the central wavelength shift of the source and the variations of the parameters of the sensing head(Verdet constant and linear birefringence) due to ambient temperature fluctuation upon the scale factor of a bulk-glass optical current transformer are theoretically analyzed and digitally simulated. The results show that the normalized output scale factor will decrease 1.379%,when the ambient temperature changes from 10℃ to 30℃,among which the effect of the central wavelength shift with temperature upon the scale factor is greater than the others. Therefore,it is necessary to adopt proper technical measures to decrease or compensate the undesirable effects of the temperature characteristics of the sensing head.

Based on the third-order aberration theory,the problem that off-axis aberrations in the main types Galilean and Keplerian beam expanders can't be corrected is worked out. With reasonable analysis of optical path,a new type beam expander with wide aperture and bigger field angle and large relative aperture in which the on-axis and off-axis aberration are both perfectly corrected is designed. It has much better optical performance than the two classical types. An example is presented. The clear entrance of its objective is 300 mm and focal length is 800 mm,its magnitude ratio is 30 and the primary working wavelength is 0.6328 μm. The results of optical design have been given. When the distances among the lenses of eyepiece and the distance between the objective and eyepiece are adjusted reasonably,the beam expander can be used in three wavelengths.

The concept of Virtual Instruments(VI) and the advantages of VI development environment LabVIEW are introduced. A virtual spectrometer is designed with LabVIEW in which light is dispersed by a prism or a grating and the whole spectrum is detected by a CCD. The intensity of light is converted to digital signals and transferred to the computer by a data acquisition device. The spectrum data are analyzed and displayed by high-integrated modules in LabVIEW,using a graphical programming language called G-Language. It is high-efficient,timesaving,easily-used and easily-extended.

Accumulation effect of multi-shot laser-induced damage to optical coatings was investigated.Laser damage testing was performed at 1064 nm with nanosecond pulses at a pulse length of 12 ns,using an accurate and reliable measurement system. Damage threshold and the number of shots were studied by a statistical method. Comparing the case of single-shot with multi-shot laser damage,it is known that microdefects in the optical coatings were responsible for multiple pulses damage to mirrors. The damage mechanism was used to explain the damage process. The expression for the damage threshold and the number of shots was founded. Nomarski microscope was employed to observe laser-induced damage morphology after laser irradiation.

The structure and principle of an optically written display based on up-conversion of near infrared light is presented. In order to improve the screen luminance and avoid the leakage of infrared light,two multi-layer interference filters are designed for the display. One is called LP filter,which has low transmittance for visible light between 420～800 nm,and a high transmittance for infrared light between 800～1000 nm;The other is called SP filters with opposite characteristics. Layer-symmetric films are used to design the filters and MATLAB is used to simulate and optimize the design. The obtained LP and SP filters have good characteristics within the whole wavelength bandwidth and the incident angles of 0°～30°. The 21-layer LP and SP filters have a total thickness of 1586.8 nm and 2157.8 nm,respectively. The manufacturing tolerances on material refractive index and film thickness are reasonably large.

The basic linear tuning principle of fiber grating wavelength without chirp effect using variational section beam with uniform intensity is theoretically analyzed in this paper. Three kinds of basic design scheme of variational section beam and the condition that the elastic beam section as tuning device of the wavelength of fiber grating without chirp effect must satisfy are presented. The characteristics of the tuning technologies using cantilever beam based on identical section and variational section are discussed. It is shown that by bring lateral load to bear on simple beam and cantilever beam a linear tuning of fiber gating wavelength without chirp effect can be realized,and the setup is simple in structure and easy to design.

According to the characteristics of superimposed multi-wavelength fiber Bragg gratings,present a mathematic model for superimposed multi-wavelength fiber Bragg Gratings. Theoretical analysis is made using Matrix method for four and eight wavelength superimposed fiber Bragg gratings. The theoretical analysis results is agreement well with the experimental results. Also,the numerical simulation of sixteen wavelength superimposed fiber Bragg gratings which wave gap equals 0.8 nm is made firstly. This method is conducive to the design and fabrication of multi-wavelength superimposed fiber Bragg gratings.

Due to different strain of different components along the grating axis when Bragg grating is employed to measure strain(statically,dynamically),central FBG wavelength shift changes accordingly. However effect of this strain difference on central wavelength shift of fiber Bragg grating is often ignored in practical application. With coupled mode theory,as well as grating segment and transfer matrix method,chirp characterizations of fiber Bragg grating are studied when axial linear and high-order strain,non-linear periodic strain-wave are applied. Based on different chirp characterizations,measurement condition and measurement range under various kinds of strain are determined.

A grazing KB microscope was designed for hard X-ray (8 keV;Cu Ka radiation) imaging in ICF diagnostic experiments. Ray tracing software (ZEMAX) is used to simulate optical system performance. The best theoretical resolution of KB microscope is about 2 micron and better than 10 micron in 200 micron field of view. W/B4C supermirror was deposited on the Si wafer substrate and the reflectivity was measured by X-ray diffraction instrument (XRD). The reflectivity of supermirror is about 20% in 0.3°bandwidth. 8keV Cu target X-ray tube source was used in x-ray imaging experiments and the magnification of 1× and 2× X-ray images are obtained.

A theoretical analysis of the in-line X-ray phase-contrast imaging with partially coherent source is presented in detail by using ambiguity function (AF). Experimental results in different conditions are presented. By comparing with absorption image,the phase contrast show high contrast and visibility of the inner structure of biological sample.

Subtracting the background of the image by the polynomial function based on the Least Square-Fit was put forward. The influence of the background being on the characteristic was reduced by the subtracting. Then,according to the structure of the workpiece,the texture was first removed in order to make the gray level even. At last,following normal distribution of the signal of the digital image,a threshold was set to make the characteristic apart.

A polarization-imaging system was developed to measure the two-dimensional diffuse backscattering Mueller matrix of turbid medium. In the system of a polarized,collimated laser beam was focused to a small point on the medium,and the multiply scattered,diffusely backreflected light around this point was recorded with a CCD camera. The system and the theory of measurement were described in detail in the paper. And then,the specular reflecting Mueller matrix of the non-polarizing beamsplitter and the two-dimensional diffuse backscattering Mueller matrix of a 1.5% Intralipid solution were measured. The result confirms that the system can avoid the specular reflectance of the sample and exactly measure the Mueller matrix of the sample.

Designing a device with high sensitivity,which is used to measure the concentration of soot based on optical backscattering. It is not only characterized by real time,on-line and continuous measurements but also because its price is cheap and it is easy to install. It achieved the relation between optical intensity and concentration of soot by theoretic analysis and measured optical intensity in different concentration by using the device which was designed by the researchars of this paper. It testified theoretic validity and achieved the curve which describe the relation between concentration and signal intensity. The experimental result shows that there is a good linear relation between back-scattering lighe intensity and concentration under the condition of lower concentration.

Based on the theory of linear polynomial fitting algorithm,the micro-displacement error of phase-shifter which can induce the rotation of fringes in the processing of phase shift is analyzed. A novel method for static interferogram analysis,named the virtual grating phase-shifting moiré fringe method that is based on virtual grating technology,phase-shifting interferometry and moiré technology,is introduced and analyzed. When the static interferogram with a certain spatial frequency in the experiment is processed by this method,the phase shift is introduced mathematically and controlled by the computer to avoid any phase-shifting error,so the dynamic phase could be evaluated. Some valuable experiments are carried out and the results are presented to show the feasibility of this error-analysis method. In terms of error analysis,the criterions to control the error are presented.

According to small moving infrared target detection in the sky background,a detection algorithm is presented through the characteristics of small moving infrared target,noise and background in infrared images are analyzed. Firstly,by utilizing the excellent quality of multi-wavelet,the infrared images is preprocessed with the proper pre-filter. Secondly,the coarse detection is performed based on differentiating tow neighboring frames in image sequence to extract candidate targets. Finally,the candidate targets are recognized by the characteristics of moving target and noise in order to detect real small moving infrared target based on. The effectiveness of the algorithm is proved by the experimental results for several real infrared image sequences.

An evaluation method based on image gray correlation algorithmic was put forward. The infrared camouflage probability was defined as an impersonal evaluation index to weigh the infrared camouflage effect through the correlation processing of the thermal images with or without camouflage measure and extracting characteristic parameters of correlation peak including peak notable degree,peak to correlation energy ratio and peak-to-background ratio. The statistic weights of different characteristic parameters were educed from the statistic results of human eyes distinguishing thermal images. So the computer image processing results can be consistent with the practical human eyes subjective distinguishing results. The experiment results show that the method is effective on evaluating the infrared camouflage effects of representative land military object.

Sources and cherecteristics of noises are analysed in optical coherence tomography (OCT) system,and influences are given on image of these noises,the method of wavelet transform combining soft threshold filtering is introduced for denoising image. The definition of image is enhanced and the image quality is improved after process. It is shown that image noises can be reduced by this method.

In the system with a mode of scanning,such as the near-field optical scanning microscopy,there is big row-noise due to the scanning mode through row by row. According to this case and the noise model of the near-field optical scanning image,and combining to analyze the characteristic of the near-field optical scanning image and its row-noise,a new algorithm removing the row-noise is proposed based on the correlation among the rows to count the compensation factor of row-noise and the change of background signal to choose this factor. Moreover,wavelet transform is used to get rid of the random noise. Experiment results show that the developed method can remove the row-noise of scanning images efficiently and quickly,and can apply to process various scanning images.

In the on-board image coding algorithm,one of the main problems in ROI (Region-of-interest) coding is to decide the scaling value. A novel algorithm for calculating entropy estimate is presented which can approximate to the actual output rate produced by bit-plane coding. Then an algorithm for deciding the scaling value of ROI is proposed by which the scaling value of ROI can be decided correctly. The scaling value is calculated according to the image being coded and the requirement,which does not need inference,with different image complexity different lifted value. So the algorithm in the paper is suitable for those images such as multi-spectral images in which the ROI position is known and their complexity different. The simulation results show that in spite of different complexity the algorithm can decide the lifted value precisely so that the whole reconstructed image quality is better.

In order to realize real-time detecting and recognizing of moving point targets,a real-time image processing hardware system,which uses TMS320C6203 as its core operational processor and FPGA as a control processor,is designed. According to the experimenting and analyzing of the detecting algorithm of the point targets,a real-time detecting software of the moving point targets is developed. The experiment results prove that the designed system can complete the detection and recognition of the moving point targets in the 10 fps,1024×1024 pixels image sequence with SNR no less than 3 dB,and the correct detecting probability is up to 96%,which can satisfy the real-time processing requirements in practice.

The Lighting Detection and Orientation System is a lighting image sensor to detect the distribution and variability of total lighting. A digital image processor scheme with CPLD+DSP is used in the system,because CPLD is used as a complex programmable logic device and DSP is used as the abbreviation of digit signal processor. Image signal collection,decoder and memory are controlled by CPLD,which can reduce the area of circuit board and make the structure of circuit board easier;and large member of image data in real-time can be managed with DSP because of its high speed digital processor characteristic.

Nonlinear magnify can zoom in objects with global context. A nonlinear mapping function based on spherical geometry model is used and nonlinear image magnify can be achieved by this mapping function in image transform. For better viewing and to avoid distortion in the center of the viewing area,linear transform and nonlinear transform are combined. The results verify that it is an effective way to magnify image with keeping both local detail and global context.

The effects of cylinder site displacements(site randomness) and cylinder radius variations(size randomness) on photonic band gaps of the photonic crystals,which consist of a graphite lattice of dielectric cylinders,have been discussed by the Order-N method with a supercell technique. The numerical result shows that the variation of the photonic band gaps for the E polarization mode is far more sensitive to disorders with a size randomness than with a site randomness. Furthermore,the influence of the disorder on light extraction of a GaN light emitting diodes model,which has a disordered photonic crystal slab,has been investigated by three-dimensional finite-difference time-domain method. The numerical result shows that the influence of the disorder is small on light extraction of this light-emitting diodes model,and the influence is random.

The selected APDs which have higher punch through voltage are used to prove single photon detection at 1550 nm communication wavelengths at temperature of above 253 K. In the experiment,a controllable nonlinear current limiting circuit is used to protect the APD operated in Geiger mode at high temperature. Single photon detection at 1550 nm communication wavelengths,cooled by a thermo-electrical cooler,were experimentally demonstrated at temperature of 257.8 K. Its dark count is 3.13×10－5 ns and single photon detection efficiency is 2.08%. The experimental data indicate that it is possible to realize single photon detection at higher temperature. The APDs operated at the temperature of above 253 K can simplify the cooling device greatly.

Properties of light propagating are studied at the interface between right-handed material(RHM) and left-handed material(LHM) according to Fermat's principle,and the leasttime principle is demonstrated unsuitable for the case anymore. The shape equations of single LHM refractive surface are derived on basis of perfect imaging condition. Defects of a LHM slab lens are also pointed out with an improved compound lens is recommended intentionally.

It is well known that the paraxial approximation is no longer valid for the beams with large divergence angle and small spot size comparable with the wavelength. Thus,a rigorous non-paraxial treatment becomes necessary. In this paper,based on the scalar Rayleigh-Sommerfeld diffraction formula,the non-paraxial approximation solution and its validity are studied. Detailed numerical calculations for the exact solution,non-paraxial approximation solution and Fresnel approximation solution of circular aperture diffraction are performed and compared;It is shown that the non-paraxial approximation solution is rigorous and valid for the diffraction of a small aperture.

A model is built when atoms in the radiation of monochromatic light. By means of the perturbation method,the probability is obtained for atoms in two energy levels. Long-time action of atoms in the radiation of monochromatic light is discussed. On the condition of the speed of atoms on the influence of radioactive field is more than the decay speed of energy level,atoms oscillate between two energy levels. Atoms and radioactive field interact. Stronger,their frequency district is wider. It is concluded that the transition speed of different energy levels does not change with the time when atoms in the radiation of monochromatic light long time.