To reduce the servo lag error in adaptive optics to correct the atmosphere turbulence distortion,a kind of neural network prediction algorithm to predict the control voltage of deformable mirror is proposed. The two-layer back propagation neural network prediction method with second-order learning algorithm used to predict the voltage of deformable mirror in advance is studied through numerical simulation,based on the atmospheric turbulence wavefront data influenced by transversal wind. The look-back frame and learning-rate parameter influencing the prediction effect is discussed. The residual error of the adaptive optic system is calculated with neural network prediction algorithm and recursive least-square (RLS) algorithm. The results show that the residual error caused by servo lag in the system is reduced more effectively using the neural network prediction algorithm than using the RLS prediction algorithm.

The deformable mirror fitting ability of wavefront aberration is analyzed through influence function matrix. A wavefront control algorithm which filters the influence of high-order mode aberration is proposed. It makes up the deficiency of the steepest descent method which cannot optimize the correction process by selecting aberration mode,and improves the correction ability of deformable mirror. Wavefront distortion of a human eye is used in the experiment as the incident wavefront. The results show that the root-mean-square (RMS) value of wavefront aberration can decline to the diffraction limit after six iterations and the frequency of the closed-loop calibration system is 15 Hz. This indicates that micromachined membrane deformable mirror adaptive optics system based on the control algorithm can meet the demand of real-time human eye aberration correction. It offers an appropriate algorithm for small and low-cost system of human eye wavefront aberration correction.

The general formulae are constructed for studing the geometric anisoplanatism of an adaptive optics by the transverse spectral filtering method. At some peculiar situations,these formulae can be expressed to classical explicit form,while in general only a numerical value can be obtained. As an example,these formulae are used to study a special laser guiding star adaptive optical system whose defocus mode are also be corrected by the natural stars,besides the tip-tilt modes as the general laser guiding star adaptive optical system.

According to the second-generation (Moderate-resolution imaging spectroradiometer,MODIS) retrieval algorithm of aerosol properties over land (C005-L),the atmospheric correction of MODIS/Terra data at Semi-arid climate and environment observatory of lanzhou university (SACOL) of (Aerosol robotic network,AERONET) in the semi-arid region of the Loess Plateau was performed by respectively using the SACOL aerosol model based on surface observation and the continental aerosol model used in 6S. The surface reflectances of the visible and near-infrared channels of the SACOL area were obtained and the 0.66vs2.12 and 0.47vs0.66 surface reflectance relation and their change with scattering angle and vegetation index were verified. The results show that the correlation of surface reflectances between 0.47 μm and 0.66 μm is stronger and more stable than the one between 0.47 μm and 2.12 μm;the surface reflectance relation of 0.47vs2.12 μm is not dependent on scattering angle.

A Zeeman slower is taken as the cooling device for Sr atomic beam injected into the magneto-optical trap (MOT). An efficient method for design and construction of the Zeeman slower,which calculated the coil distribution exactly matching the analytical magnetic field by computer program,is proposed. The flow chart and the algorithm structure of the optimization design program are illustrated in detail. The experimental magnetic field produced by Zeeman slower coils and the signal from magneto-optical trap (MOT) are measured. Based on the computer program simulation,the model can be flexibly adjusted according to the experiment. The coil distribution can calculated by matching the change of parameters and analytical magnetic field. The RMS value between calculated field and analytical field is 2.17×10-4 T.

Amplification and simultaneous phase regeneration are necessary for phase modulated optical fiber communication system. In this paper,using semiconductor optical amplifier (SOA) as nonlinear medium,a nonlinear Mach-Zehnder interferometer (MZI)as the regenerator is designed. The formula of signal after the SOA based MZI regenerator is educed. For different incident power of signal,the relations between signal-pump phase difference and signal gain are discussed. The optimum parameters of input signal and pump are obtained. The distributions of phase and intensities for both the non-regenerated and regenerated signal are simulated. The results show thatthe SOA based optical regenerator has a good regeneration.

Dispersion monitoring is a key technique of realizing high-speed optical communication. The structure can be integrated on a chip when using the nonlinear effects of optical waveguides to monitor dispersion. Silicon optical waveguides have notable nonlinearity with the nonlinear refractive index as 5×10-18 m2/W. When the signal and the pump light go through the silicon optical waveguide after being coupled,high nonlinear effects,such as self-phase modulation (SPM) and cross-phase modulation (XPM) will occur. These effects will induce changes in the spectrum of the optical signal. The different dispersions of the link lead to different extent effects of SPM and XPM. By effectively setting the central frequency and bandwidth of the filters,the different spectrum changes related to SPM and XPM can be detected simultaneously,so to monitor the link dispersion can be realized. The monitoring dispersion range reaches ±40 ps/nm.

An optical current transformer is constructed by exposing gain mangetostrictive material (GMM)-FBG system to current-induced magnetic field. Ferro-magnetic materials are used to design a loop to constraint and conduct the flux into GMM. The permanent magnetic material is used in loop to establish a bias flux to form a working bias for the system. Finite element method is used to analyze and design the loop structure and the size. Coarse wavelength division multiplexing (CWDM) device is used to demodulate the alternating strain on FBG caused wavelength drift to realize sensing of the current. In the experiment,the maximum current is 186 A and the full scale accuracy is 4.3% when the system workes in linear region by setting the bias in 30 kA/m. Fast Fourier transform algorithm (FFT) is used to analyze the harmonic component of the output signal to evaluate the quality. It is demonstrated that the output signal is not influenced by hysteresis and nonlinear effect of GMM in linear region.

For the normal single-mode optical-fiber,the frequency shift and optical power of Brillouin scattering light are the functions of the temperature and strain. So,the temperature and strain of the optical-fiber can be obtained together,when Brillouin frequency shift and the optical power are able to be detected simultaneously. Brillouin optical time domain reflectometer with coherent detecting is suitable for long-distance distributed sensing,but there exist two critical problems. One is the polarization relative detecting signal;the other is how to demodulate the wideband photoelectric signal. The orthogonal polarization diversity reception and real-time wavelet transform are adopted to deal with these problems,in order to get the frequency and power of the scattering light at the same time. The experimental procedures and results are presented in the text. A laboratorial system of 25 km distributed Brillouin optical time domain reflectometer is achieved for two-parameter sensing.

We experimentally demonstrate three schemes of pumping including single pump,orthogonal-dual-pump and copolarized-dual-pump based on four-wave mixing (FWM) in semiconductor optical amplifier (SOA) for the wavelength conversion of optical amplifier (OFDM) signals. In experiment,the signal continuous-wave (CW) lightwave is modulated directly by 2.5 Gb/s OFDM. The modulated signal lightwave and pump light are coupled and then amplified before they are injected into the SOA for wavelength conversion. Experimental results show that the newly converted wavelength signals carry the original OFDM signals. The bit error rate (BER) curves and received constellations are also measured by experiment,the experimental results show that the copolarized-dual-pump configuration has the smallest system power penalty,which agree well with the theoretical analyses.

An optical waveguide microring resonator for picosecond switching window generation is reported. The design and simulation are presented. The multiple-ring-cascaded structure is adopted to design the transmission characteristic curve of the microring resonator. Utilizing the nonlinearity of the transmission characteristic curve,a narrow switching window can be generated with a sine-wave electrical control signal to shift the refractive index of the material. The modulation characteristics and switching window are researched with coupling matrix formalism. The dependences of the width and extinction ratio of the switching window on the driving voltage are analyzed. Results show that the width,extinction ratio and the insertion loss of the switching window driven by 10 GHz electrical voltage are better than 10 ps,40 dB and 1 dB,respectively. The proposed picosecond switching window generation technology only requires electrical control signal instead of high-quality optical control pulse. It possesses a high operation speed with simple structure,low transmission loss,high extinction ratio and low operation voltage.

The oscillations of the bending loss for single-mode fibers with the bending radius and the temperature are investigated experimentally by use of fiber loop cavity ring-down technique. When the fiber is bent,the light ejects from the fundamental mode to form whispering gallery (WG) modes produced by reflection at the cladding-coating interface,or at the coating-air interface. On the synchronous coupling condition,the light from the WG modes will couple back and interfere with the fundamental mode,which leads to bending loss oscillations. The experimental results demonstrate that the bending loss follows an oscillatory and exponential growth trend when the bending radius decreases from 27.63 mm to 9.33 mm. In addition,the secondary oscillations are observed because of the secondary coupling between the fundamental mode and the WG modes. Change of the bending loss with temperature is oscillated,and the oscillatory period decreases with the decrease of the bending radius and the increase of the temperature. The locations and the amplitudes of the loss peaks and the oscillatory period are consistent with the theoretical results.

Difficulties often arise when digital image correlation (DIC) method is used for serial image matching in nonlinear and large deformation applications. An improved algorithm is proposed by utilizing the concept of fractionized displacement transfer (FDT). For a series of image that records the deformation process,the matching algorithm automatically rechoose an intermediate image as the reference image when the correlation level between the current reference and target images drops below a given threshold. Then the sub-pixel corresponding points in the new reference image are rounded into intergral pixels to facilitate the subsequent DIC matching procedure. A method,which is specifically designed based on the continuum assumption,is proposed for compensating the loss of accuracy caused by the pixel rounding. In addition,a growing method for obtaining initial matching points is proposed,which proved to be able to improve the matching effect and efficiency. The reference images are chosen in terms of the ratio of the number of points in the initial matching set to the number of matched points obtained by the correlation method. Experiment and accuracy analysis demonstrate that the proposed technique is effective and reliable,the matching accuracy is on the order of 0.01 pixel.

On the basis of natural suture algorithm of fade in and fade out,a novel image automatic mosaic algorithm based on hardware is presented in order to capture whole and massive printed circuit board (PCB) photoelectric image,and its basic principle is analyzed. Noise in the PCB photoelectric image is filtered through median filtering. Because of the character of unitary obscuration of the image captured and its gray redundance in image histogram,a novel algorithm of image enhancement that combines removing gray redundance and using gray transform is presented,and its basic principle is analyzed. The whole and massive PCB photoelectric image is captured by the image mosaic algorithm proposed in the experiment. After image preprocessing,the enhancement result of the small part of the whole and massive PCB photoelectric image with our enhancement algorithm is better than that by other enhancement algorithms on the aspects of subjectivity and objectivity.

The image stitching based on feature point is not only invulnerable to the light,rotation and other factors,but also helpful to increase efficiency. It has become one of the most attended methods. Scale invariant feature transform (SIFT) is a better coner extraction algorithm,but there are still some problems in the matching step. A new matching principle based on system similarity theory was proposed,and then it was compared with the traditional matching principle. The problems with tradtional matching principle was pointed out,and also the precision and speed of the new principle was tested ,and the reason why the new principle get higher precision was analysed. By the new principle the matching features were detected successfully. And then,the transform matrix was calculated by the progressive sample consistency algorithm. Further more,it was optimized by the Levenberg-Marquardt (L-M) algorithm,and finally automatic image stitching was realized . At last,the stiching result of panorama camera image was given,further discussion about the new matching principle was also given in the end of the paper.

A simple mathematical model is set up to investigate the effect of platform vibration on the image quality in an airborne strip-mode synthetic aperture ladar (SAL) based on the work of Park. Numerical simulation is carried out to show the influence of the vibration parameters such as amplitude,frequency,initial phase,or peak acceleration,on the SAL image resolution within the frequency range of 0-500 Hz. SAL image of ideal point target or extended surface target with or without vibration is given. The simulation results show that the quality of SAL image is most correlated to the peak acceleration of the platform vibration. With higher acceleration,the SAL image deteriorates severely. As illustrated in the simulation,the SAL image is acceptable as the peak acceleration is no more than threshold and will be totally distorted in the azimuth with many ghosts as the acceleration is greater than another threshold. In addition,the simulation results also indicate that initial phase of the vibration plays an important role in deterioration of the SAL image induced by the vibration.

The folded optical structure used in 4f-based planar-integrated opto-electronic hybrid correlator system,increases aberration and reduces the system′s recognition ability. The phase modulation function of micro-optical lens is determined,by using the theory of oblique incidence corrdinates to analyse planar integrated optical correlator structure. Then the system aberration is reduced and thereby the recognition ability is enhanced,by analysing the phase function of micro-optical lens elements and using Zemax software optimization system. The optimized system′s maximum optical path difference is less than λ/4 and the system attains diffraction limited performance. The contrastive and quantitating analysis is simulated by Matlab,the result show that the optimized system′s recognition performance has been improved by 0.8 times. It shows that the aberration has been improved well,the system′s recognition ability has been significantly enhanced.

To meet the demand for stars detection by all-time optical measure equipment in the ship,and remove the problem of observable stars in the daytime by TV measurement as well as keep inertial navigation equipment emending its direction continuously ,so that Space Tracking,Telemetering and Commanding ships “YUAN WANG” can realize their sophisticated measuring and tracking,the technique of “real-time variable multi-levels spectrum filtering”,which can distinguish dark and small star target from the bright background of the sky,“the algorithm of dark and small target′s stable recognition”,which realizes quick and stable targets recognition and tracking,and “the methods in software radio design”,which realizes the composition of the processing system and the application of the algorithm are adopted. The optical measure equipment can detect the stars of magnitude 4.5 or even bigger ,and the amount of stars that can be detected in the daytime can reach 250 or more,based on that optical equipment′s aperture equals 180 mm and its focal length equals 3000 mm. The ability of maximum grades of star detection in the daytime can reach the grades in night,which expandes working ability of the optical equipment that now uses in ships to its limitation. The method can be popularized and applied in many other fields of dark and small targets detection by TV.

The basic principles of wave-front sensing based on phase diversity (PD) are expatiated. An improved PD based on genetic algorithm (GA) is proposed for the highly nonlinear character of PD′s objective function. The parallel and global search features of GA are suitable for the global optimization of PD by analyzing the characters of GA. A sparse-aperture system composed by three sub-apertures with different piston errors is established. The changes of the optimization objective function are analyzed and the new PD based on GA is used to find the global optimal value of the system. The results of many experimental simulations show that:GA can find the global optimum value of the sparse-aperture system,and the root mean square (RMS) between estimated piston error found by GA and the true piston error is 0.04λ. The new PD has a high accuracy.

The measurement of magnetic field through the polarization dependent loss (PDL) of phase-shifted grating is a more novel approach. It can be used to measure the pulse alternating strong magnetic field. The key issue of fiber grating sensor is the cross-sensitive. Ignoring the inherent birefringence of gratings,the principle of magnetic field sensing is derived and simulated by transfer matrix method. The influence of the temperature,axial stress and pressure on the transmission window of phase-shifted grating is theoretical analyzed,and the corresponding changes of the PDL peak value are simulated. The results show that the wavelength of transmission window peak value changes linearly with temperature and axial stress,PDL spectrum horizontal lines shift,and the result of magnetic field measurement will not be affected. The refractive index changed with pressure causes the irregular change of PDL spectrum,having a serious impact on the magnetic field measurement.

A high-accuracy radiation calibration system of vacuum ultraviolet (VUV) detector is established,to meet the development of the ultraviolet (UV) and VUV remote quantification. In 120-220 nm spectral range,the absolute responsivity was transferred to EMR541-09-17 ultraviolet phototube detector,on the basic of national institute of standards and technology (NIST) ultraviolet standard detector. According to the guidelines for evaluating and expressing the uncertainty of NIST measurement,the relative uncertainty of transferring is less than 2.4%. The aim of high accuracy radiation calibration of ultraviolet detector in VUV region has been obtained.

A new phase unwrapping method to extend the discontinuous wrapped phase with linear carrier before unwrapping is presented. First,the carrier frequency is determined by the Fourier transform method. Then the least-square method is used to calculate the linear carrier which matches with the wrapped phase to extend the background and obscurations region. Finally,the classical quality-guided method is used to unwrap the extended phase map. The experiment result shows that,for the discontinuous interferograms with large linear carrier,the unwrapping result avoids the global errors between different regions. The computer simulation result shows that,the method can be applied to discontinuous interferograms with small linear carrier or without carrier and get the correct unwrapping result can be obtained after linear carrier modulation.

The Doppler-free saturation fluorescence spectra system is set up. 100 kHz narrow-band dye laser and photodiode are used in this system. Two counterpropagating dye laser beams overlap on a Na cell whose temperature is set at 65 ℃. And a photodiode located at one side of the Na cell collects and detects the excited fluorescence. Then photodiode signal is sampled by data acquisition card which is controlled by LabVIEW software. Doppler-free features D2a,crossover and D2b are observed by scanning the dye laser frequency. When the dye laser frequency scan step is about 2 MHz,three lines in the D2a can be observed in this experiment.

Focusing and leveling measurement system(FLMS),as a key subsystem of the scanner,is used to detects height and tilts between wafer exposure area and the projection lens in real time. Its performance greatly affects the image quality of projection lens. Based on the grazing-incident beam method ,FLMS detects height and tilts by using more than 3 probe spots on wafer exposure area. Spot position errors cause measurement errors and defocus of exposure area which affect the image quality. Based on the one-spot measurement model,position error model of probe spot is presented. It is found that the height measurement error is proportional to the spot position error,and the accuracy caused by spot position error is less than 10 nm when the zero plane of FLMS is well adjusted,and spot position error is 0.05 mm.

Theoretical research on the mode locking characteristics of mode-locked all-solid-state laser with semiconductor saturable absorber mirror has been carried out. According to theoretical model of suppressing Q-switched mode locking and combining with LD-pumped all-solid-state Yb:YAG laser,the reflectivity of SESAM and the critical pump power of suppressing Q-switched mode locking have been studied by numerical simulated calculations under the conditions of different modulation depths,non-saturable losses,saturation fluences,transmittance of the output mirror and other parameters. When the incident pulse fluences on the SESAM are the same,modulation depth,non-saturable loss and saturation fluence have inverse relations with SESAM reflectivity. With the decrease of modulation depth,saturation fluence,transmittance of the output mirror,beam waist and cavity length,the critical pump power also decreases,and suppressing Q-switched mode locking becomes easier. When the crystal length is 1.9 mm,the minimum critical pump power can be obtained.

To meet three-step 3ω temporally shaped pulse (the pulse-width ratio of three steps is 1.5 ns:1 ns:0.5 ns and the amplitude ratio is 1:4:16) required by phgsics experiment,preliminary laser-pulse-shaping experiment is performed on technical integration line (TIL). Firstly,laser energy and pulse shape of the injection laser system (pre-amplification system) are primarily predicted to tune out systematic differences among the eight beams by laser performance simulation model according to the shot mission and previous data.Secondly,several laser shots at different laser power are done to further modify the pulse shape:1ω energy and 1ω pulse are corrected by the experimental frequency conversion efficiency for every beam,The injection laser energy by fitting experimental input and output energy data,and the injection pulse shape by gain-fluence curve based on the above corrected 1ω pulse and 1ω energy. Finally,all the injection pulses are compromised again for the final pulse shaping. The experimental 8-beam three-step pulses of 3ω at target are comparatively consistent with the requirement. For 3ω-3 ns-0.5 kJ (single-beam) pulse,the three-step beam-to-beam instantaneous root mean square (rms) power imbalance are about 30%,10% and 5%,respectively.

A three-dimensional finite element thermal analysis model is presented for a micro-channel heat sink packaged semiconductor laser diode array(LDA). The transient and steady-state temperature distribution of the laser diode array is simulated when it works under the condition of 20% high duty cycle. It is found that the temperature of the active region rises slowly within the first few dozen microseconds after turning on current. And then,the temperature rises rapidly due to the heat flux interleaving between adjacent emitters,and finally a steady state is reached due to the thermal relaxation and accumulation effect. The static temperature distribution presents periodicity as the same of the array structure and no temperature difference exists among each emitter. The temperature rising concentrates in the electrode region of the active layer,and the temperature drops rapidly in the insulated region. The emitting facet has a higher temperature,and a max 3 K temperature difference exists along the cavity when the working current is 180 A. The output characteristic of the laser diode array is measured when it works under different currents. The temperature rising of the active region and the steady-state thermal resistance are basically coincident with the simulation.

Based on the Sellmeier equations of Kbe2BO3F2 (KBBF),non-collinear phase matching conditions and Newton-Raphson iterative approach,the type-Ⅰsecond harmonic phase-matching angle,effective nonlinear coefficient and the acceptance angle of KBBF crystal whose fundamental-wave wavelength is 1064 nm are respectively calculated with numerical method,under the non-collinear phase matching. The results show that the non-collinear phase matching can be realized when the angle of the first fundamental-wave angle is 20°-85°. Accordingly the angle of the second fundamental-wave the double-frequency wave is 29.1°-52.7°and 24.6°-68.83° respectively. The effective nonlinear coefficient decreases and the acceptance angle increases as the first fundamental-wave angle grows. When the first fundamental-wave angle is 26.1°-26.8°,both of them have an oscillation phenomenon.

Due to the partially coherence property of single laser beam and bandwidth of phase control system,partially combination is often obtained in coherent beam combining of high power lasers. The propagation property in free-space of partially coherent laser array in the case of residual phase error is analyzed,and the analytical expression of far-field intensity distribution is deduced. The influence of coherence of single laser beam and residual phase error on the combined beam quality is studied.

On the experiment of inertial confinement fusion,the success of implosion experiments is depended on the irradiation uniformity. In order to improve the uniformity of laser imtensity,time smoothing technologies are always applied with spatial technologies. Technology of smoothing by spectral dispersion is one of the familiar time smoothing technologies,and spectral broadening is the core technology. To improve the effect of spectral broadening,a double-pass phase modulator which would meet the need of spectral broadening of technology of smoothing by spectral dispersion is designed instead of the old single-pass phase modulator. The matching condition under double-pass modulator is calculated theoretically,and a satisfying result is also attained in the experiment,so the feasibility of double-pass phase modulator is validated. Based on the above discussion,another idea of multiple-pass phase modulator is mentioned.

A novel monocular camera based on road vehicle detection and trcking approach by fuse multi-cues of object is present to improve drive security by providing some effective on road vehicles position information for driver. First,the horizontal symmtery of vehicle rear view is utilized to achieve the region of interest (ROI) extract so as to reduce search area of following process. And then,the sign of underneath shadow is employed to generate hypothetical positions on which potantial vehicles maybe present. Following,both image intensity and figure information are combined to used to verify the vertical symmetry of the potential vehicle candidates. Meanwhile,mean shift procedure,based on the object feature model of combine color histogram and orientation histogram,is employ to fast search the potantial objects between two sequential image frames. More improtant,both detection and tracking cooperate work under a interactive mechanism which can dramatically improve both detection efficiency and real-time. Experimental results show that the propsed apporach can achieve 96.34% correct recognition rate and run on an average 24.27 frame/s,which validate the vehicle drive security and real-time requirements.

A new white phosphorescent glass-ceramic Eu2+/Eu3+ doped SiO2-Al2O3-ZnO-K2CO3 is prepared by the melt quenching method and subsequent heat treatment. It′s X-ray diffraction (XRD) pattern,excitation spectrum and emission spectrum are measured and recorded at room temperature. By the X-ray diffraction diffusion (XRD) data,βZn2SiO4 is demonstrated to be the crystallites in the glass-ceramic. Based on the Scherrer equation,the average size about 35 nm of βZn2SiO4 nanocrystals is calculated. The intense blue emission band (400-460 nm) and red emissions (574,587,611,650 and 700 nm) assigned to 4f65d→4f7 transition of Eu2+ ion and 5D0→7FJ (J=0,1,2,3,4) transitions of Eu3+ ion respectively. They are simultaneously observed at room temperature under 372 nm excitation in the glass ceramics and the emission luminescence intensity increased significantly compared with the as-made glass. The results indicate that Eu2+/Eu3+ doped SiO2-Al2O3-ZnO-K2CO3 glass-ceramic can act as suitable materials for LED phosphors.

Fabrication of quantum dots (QD) by pulsed laser on SiGe alloy samples is reported. After annealing,some peaks of stimulated emission were observed in the region of 720-800 nm which have threshold behavior obviously. It was found that the peaks of stimulated emission have an obvious red-shift from Si QD to SiGe QD. Oxide layer on SiGe quantum dots involves Si＝O bonds and Ge＝O bonds according to the Fourier transform infrared spectroscopy (FTIR),which could produce the localized gap states of electrons (or even the trapped exciton). Calculation shows that Ge＝O bonds emerging on SiGe QD could decrease the distance between the valence band and the localized gap states which can interpret the red-shift of stimulated emission on SiGe QD.

A type of quadrangular frustum pyramid composition nanostructure with silver in bottom layer and gold in top layer is investigated. Based on discrete dipole approximation,localized surface plasmon resonances of metal composition nanoparticles induced by optical excitation is investigated. A detail discussion is given on the extinction properties and the refractive index sensitivity of quadrangular frustum pyramid nanoparticles in different sizes,metal composition ratios and so on. The result of calculation shows that the refractive index sensitivities of quadrangular frustum pyramid composition nanoparticles with sliver layer in 50 nm thickness keep the same value as increasing the thickness of gold layer. It is also observed that the peak wavelength blue shifts as increasing the thickness of quadrangular frustum pyramid nanoparticles and red shifts as increasing the Ag concentration in the composition nanoparticles with the same shape. Especially,if the thickness of quadrangular frustum pyramid nanoparticles with structure of gold adding to silver is more than the mean free path of conduction electrons,the excitation intensity of localized surface plasmon resonances won′t change any more with increasing the thickness of added gold.

The Eu3+ rare-earth organic complex with double ligands of TTA and 5NO2Phen is synthesized. The characteristics of this compound are studied by elemental analysis,TG-DTA,infrared spectra,UV-visible absorption spectra. From the UV-visible absorption spectra,it can be seen that there are two absorption peaks locating at 340 nm and 270 nm,which correspond to the absorption peaks of TTA and 5NO2Phen,respectively. Under the excitation of 350 nm light,three characteristic emission peaks of Eu3+ ions are obtained:5D0→7F0 (583 nm),5D0→7F1(593 nm) and 5D0→7F2(612 nm) . Experimental results demonstrate that the ligands can transfer the absorbed energy to Eu3+ ion. The ligands can effectively enhance the luminescent performance of Eu3+ ion. Electroluminescence devices ITO/PEDOT:PSS/PVK:Eu(TTA)35NO2Phen /BCP/Alq3/Al based on Eu complex as the active layer are fabricated,and the red emission color coordinate is about (x=0.51,y=0.31) under 18 V driving voltage.

Absolute band gaps of the two-dimensional triangular-lattice photonic crystals consisting of Ge rods are calculated with the finite-difference time-domain method. Through calculating the band structures of the triangular-lattice photonic crystal consisting of hollow circular Ge rods,it is found that the TM-polarized and TE-polarized photonic band gaps can be overlapped,and an absolute photonic band gap can be obtained. A large absolute band gap of 0.074 (2πc/a) can be obtained for the structures with a triangular lattice of hollow triangular Ge rods immersed in air,corresponding to 16.2% of the central frequency.

Based on multipole method and coupled-mode theory,the transmission spectrum of a typical hexagonal lattice photonic crystal fiber Bragg grating is analyzed and simulated by Matlab. The differences between conventional fiber grating and photonic crystal fiber grating on their transmission spectrum and delay characteristics are compared,and derived qualitatively. The apodization characters of this fiber grating are also researched,the optimal apodization function and corresponding transimission spectrum are obtained. It is found that the effective refractive indexes of core mode decline as wavelength rising,compared with the conventional fiber grating,photonic crystal fiber grating has the shorter resonant wavelength,when it is added chirp,10 cm photonic crystal fiber grating can provide 1200 ps linear delay.

Two kinds of marine microalgae,chaetoceros gracilis and platymonas subcordiformis which have high economic value as research object,are setected to do the culture experiment in incubator with light red,green,blue,white-LED spectrum of different combinations compareing with the traditional fluorescent. By comparing the growth rate with the fluorescent light,it′s showed that LED light source spectral composition is more effectively to promote the growth of microalgae. The obvious advantages of LED as light source of microalgae are indicated.

Phase retrieval of in line X-ray phase contrast computed tomography (IL-XPCT) with Born approximations is achieved by using images recorded at single sample-to-detector distance. Experiments are carried out at X-ray imaging and biomedical application beamline,by taking a phantom and a locust as the samples. After phase retrieval,much better IL-XPCT slices and three-dimensional rendered images are obtained. The results show that the potential application of the proposed method to three-dimensional non-destructive imaging of biological samples.

Experimental measurements on the phenomenon of pulse distortion which is induced by the stimulated Brillouin scattering (SBS) in the ytterbium-doped double-clad fiber amplifiers with the single-frequency pulse amplification are presented. In the experiment,the 14 m double-clad single-frequency amplifier with the inner-clad mode diameter 130 μm and the fiber core mode diameter 6.5 μm is adopted. The backward stimulated Brillouin scattering (SBS) pulse is observed when the peak power is up to 3.3 W in the single-frequency pulse amplification with the pulse duration of 200 ns. The pulse width of SBS pulse is apparently narrower than that of the input signal pulse. The stochastic aspect of pulse distortion and power property induced by SBS are analyzed. Meantime the frequency shift of SBS is verified using the F-P interferometer with free spectral range of 30 GHz.

The characteristics of Z-scan curves for strongly nonlocal nonlinear medium with finite size,such as lead glass and nematic liquid crystals,are studied. By employing the transformation of the q-parameter,we obtain the normalized transmittance curves based on the thermal-lens model. It is found that the influence of the boundary condition on the transmittance can be neglected,and the peak-valley position and their difference depend on the incident power. Experiments are carried out in lead glass,and the characteristics of the curves are verified with different incident power,and the nonlocal parameters of lead glass are obtained.

The nonlinear optical and optical limiting properties of the perfluorinated phthalocyaninatotitanium (IV) oxide (F16PcTiO) and its derivative F16PcTiO2PhCHO have been studied. Compared to F16PcTiO,the peak maxima of the Q-band of F16PcTiO2PhCHO is shifted to the red by Δλ=7 nm. Z-scan experimental results show that F16PcTiO exhibited much greater nonlinear absorption coefficient and lower saturable fluence for optical limiting when compared to F16PcTiO2PhCHO in solution. The latter displays much better optical limiting performance in chloroform than in toluene. In contrast to the highly soluble tetra (tert-butyl)-substituted titanium (IV) phthalocyanines,i.e.,tBu4PcTiO and tBu4PcTiO2PhCHO,the perfluorinated titanium (IV) phthalocyanines display stronger intermolecular interactions which are driven by enhanced Van der Waal′s attractive forces between phthalocyanine rings,and reducs the effective nonlinear absorption and the solubility in common organic solvents as well.

The partial response maximum like-hood (PRML) can not be directly used for the signal waveform modulation (SWM) multi-level (ML) recording,because in SWM ML,the signal after time recovery does not respond to a symbol sequence. An adaptive level detection method based on minimum Euclid distance is proposed. The Euclid distance between the actual waveform and reference waveform is employed for the level detection. Adaptation can make the set reference waveform approach the actual waveform. The protection mechanism can prevent the case that the reference waveform greatly deviates from the actual. Experimental results show that,without adjusting parameters,this detection method can achieve a low level error ratio,which is less than 2×10-4,for different disk batches. It also has capability for disks with defects. Using this level detection method,the playback system realizes stable and continuous playback of high definition video.

SiSb films are deposited on the polycarbonate optical discs by direct current magnetron sputtering technology. Discs with SiSb films are initialized at laser power 400,500,600,700,800,1200 mW,respectively,by phase change optical disc initializer. The transformation of reflectivity at wavelength from 300 nm to 800 nm of films initialized at different laser power is compared. The results illustrate that reflectivity and reflectivity contrast of SiSb films increase gradually with the enhancement of initializing laser power. Reflectivity contrast of the novel SiSb films initialized at laser power 1200 mW is as high as 30%-35%,which indicates novel SiSb phase change material is a promising material for optical data storage. X-ray diffraction is performed on the as-deposited SiSb films and those laser-initialized at laser power 400,800,1200 mW,respectively. The study shows that the as-deposited SiSb is amorphous state,crystallization to different extent in the samples initialized at different laser power takes place,and the higher the laser power is the higher the degree of crystallization in the samples. Crystallization phase of the samples is hexagonal rhomb-centered structure of antimony,which is similar to the structure of thermal annealing SiSb films reported by other papers.

A special kind of long focal-length optical system using annular aperture which is expected to be used in space cameras optical imaging system is introduced,it can also considered as a kind of sparse aperture system. Light enters the optical system through an outer annular aperture and is focused by a series of concentric annular reflectors and compensation lens to the image plane. They have large obscuration ratio. They have compactness and good image quality,which is expected to be used in micro satellite payload with high resolution. The result of a long focal length optics with six-fold reflection is introduced. Their performance evaluation and tolerance analysis are given and compared.

One new-style unobscured three-mirror optical system was designed,which was based on the Gregorian system. The design step of this special three-mirror optical system was analyzed,and then a system with effective focal length of 900 mm,field of view of 0.8°×0.8° and F-number of 9 was designed. Its total length is 330 mm. The image qualities of the example are near diffraction limit. The system has advantages of shorter physical size and better ability in restraining stray lights. Compare with other three-mirror optical systems,the most prominent advantage of this special three-mirror optical system is that it just uses two aspheric mirrors and one spherical,thus reducing the cost and the manufacturing difficulties a lot.

A new design approach about Offner-type imaging spectrometer is presented based on the relation between the meridianal focusing curve and the sagittal focusing curve. It can be not only applied to the Offner-type spectrometer with the three concentric components,but also the traditional Offner-type spectrometer with two concentric components. What′s more,it can be flexibly optimized based on existing components,which overcomes the complexity and pertinence of the existing methods. The procedures of the tangensy and intersection relations of the meridional and sagittal focusing curres and the design of existing components are shown. An example of optimization design with the existing components is presented. With the relative aperture of f/3.2,the smallest RMS spot radius of 2.3 μm at the wavelength range of 400-1000 nm can be achieved,which is very close to the diffraction limit at the wavelength of 1000 nm. An imaging spectrometer is developed successfully using the above parameters,which can achieve the indexs after preliminary test finally.

The power-referenced refractometer based on tilted fiber Bragg grating is investigated theoretically by complex mode coupled mode theory. The use of perfectly matched layer (PML) technique simplifies the radiation mode model. The numerical results show that with the increase of tilted angle,the sensing range shifts to smaller refractive index region. With the increase of the grating length and the index modulation strength,the sensitivity of the refractometer increases,but sensing range unchanged. This refractometer is polarization dependent,and the polarization dependency raise with the increase of grating tilted angle. Therefore,precise and stable polarization control is essential for such kind of sensing system.

Transmission and extinction characteristics of a novel double-layer sub wavelength metal grating polarizer at visible region are investigated theoretically. The difference between the polarizer proposed and conventional lies in that the high refractive index dielectric layer is inserted between the substrate and grating,which icrease the transmissivity and extinction ratios. By using rigorous couple-wave analysis (RCWA),the transmissivity and extinction ratios of transverse-magnetic wave (TM) polarization are analyzed as a function of the thickness of the high refractive index dielectric layer and the duty cycle. Simulation results show that the transmissivity is more uniform compared with that of the conventional type in visible region. When the incident angle range is 0-60°,the TM transmissvity is still about 79% and the extinction ratios is higher than 50 dB. The polarizers is very compact and suitable for backlight unit used in liquid crystal devices.

High-precision KDP optical element is a key component in ICF optical system. The micro-waveness on the machined KDP surface has a significant impact on its transmittance. The effect of micro-waveness amplitude and period on the transmittance of KDP optical element is discussed by Fourier modal theory. Results indicate that:the transmittance increases linearly as the micro-waveness amplitude grows (about 0.5% per 10 nm) when the micro-waveness amplitude is less than 100 nm;the transmittance varies around the central value while the transmittance amplitude remains unchanged,and both of them increase as the micro-waveness amplitude grows. The transmittance is very low when micro-waveness period is between 10.5 μm and 12 μm,and measures should be taken to avoid micro-waveness period in such range. Processing,detection experiments of morphological surface and transmittance of KDP crystal are carried out,and the experimental results are consistent with the theoretical calculations basically.

The wavelength selective switch (WSS) is now considered to be the most important wavelength engine technology,and will be the key component of next-generation optical networks for carriers all over the world. A novel WSS is theoretically and experimentally presented in this paper,which implements an one dimensional MEMS mirror to realize the function of wavelength switching,while the Hitless switching is achieved by a MEMS attenuator. Compared with traditional WSS implementing two dimensional MEMS mirror to achieve the two functions simultaneously,this novel WSS is manufactured based on mature technologies,so it is cost-effective and productive. The maximum attenuation of 34 dB,insertion loss of 6.4 dB,dispersion range of -1.64-6 ps/nm are reported,indicating a high uniformity with the simulation results.

The cavity field spectrum of the Jaynes-Cummings model is investigated. The results for the initial fields in superposition state of zero and one photon Fork states (a qubit of cavity field) are presented. The relation of the spectral structure and the initial field qubit is analyzed. The result shows that the influence of probability amplitude of the initial field qubit on the spectral structure is sensitive with one-to-one correspondence between them. No information about the quantum phase of the qubit can be gained from the cavity field spectrum.

On the basis of studying the concept and solution of spectral compression,a kind of novel compression solution is proposed. Different from spectral compression via algorithm,our solution focuses on optical system. A coded aperture is utilized,and the coding process is snapshot,and decoding algorithm corresponding the coding form to reconstruct the spectrum is chosen. Two kinds of specific coded aperture are presented which are based on wavelet transform and deficiency matrix. Decoding reconstruction via inverse wavelet transform and gradient projection for sparse reconstruction iterative algorithm is presented. Then compressive ratio and fidelity of two kinds of coded aperture are demonstrated by comparison of the spectral simulating acquired via the real spectrometer. It is possible to reconstruct signal-specific information at the lowest sampling rate,and the general principle of coded aperture compression is summarized.

Near infrared (NIR) spectroscopy was applied for the fast determination of proline in oilseed rape leavers. The oilseed rape leaves were treated by herbicide,248 samples were collected for NIR spectral scanning within the wavelength region of 1100-2500 nm. Smoothing way of Savitzky-Golay with 7 segments,standard normal variate (SNV) and second derivative were used as preprocessing methods of spectral data before the calibration stage. Partial least squares (PLS) analysis was applied as calibration method as well as a way to extract the new eigenvectors which could be used to represent the most useful information of original spectra and compress the spectral dimensionality. The selected new eigenvectors were used as the input data matrix of back propagation neural network (BPNN) and least squares-support vector machine (LS-SVM) to develop the BPNN and LS-SVM models. The calibration set was composed of 186 samples,whereas 62 samples in the validation set. The results indicated that LS-SVM model achieved the best prediction performance,and LS-SVM model outperformed PLS and BPNN models. The correlation coefficients (r),root mean square error of prediction (RMSEP) and bias by LS-SVM model were 0.995,0.041 and 0.000,respectively. The overall results demonstrated that NIR spectroscopy combined with LS-SVM model could be successfully applied for the determination of proline in oilseed rape leaves treated by herbicide.

As the key components of the IR optical systems,infrared (IR) antireflection (AR) coatings are such important topic and the study of them are so complex. According to the demands of germanium(Ge)windows for the researching project,non-symmetrical equivalent layers theory are adopted to design the multilayer broadband AR coatings. The optical coefficients of the coating materials are fitted at established technics conditions and all the fitted optical coefficients are used in the layer thickness optimization process. A theoretical design approaching to the factual situation is obtained. After the optimization of the deposition technics,high performance broadband AR coatings are finished. The average transmittance of the spectrum tunnels such as 3.5-4.0 μm,6.3-7.6 μm,10.3-11.3 μm is more than 96% and the average transmiffance of the tunnel 11.5-12.5 μm is more than 94%. All the AR coatings can experience the environment tests and meet the optical system′s request.

Zinc selenide (ZnSe) is widely used for infrared (IR) optical systems because of its wideband transmission region. However as a substrate,it is very difficult to deposit ultrabroad band multilayer antireflection (MLAR) coatings in IR region,especially for the durability. 2-16 μm ultrabroad band MLAR coatings on ZnSe are designed and produced many times by ion beam assisted electron-beam deposition. The absorption rate of YF3 at 3400 and 1640 cm-1 is found by deposition single ZnSe and YF3 films on Ge substrate. Finally,2-16 μm ultrabroad band MLAR coatings are deposited by using BaF2 and YF3 as the low-index materials. DLC films are deposited on external MLAR coatings by pulsed vacuum arc ion deposition.The measured results show that the average transmittance is greater than 93%,the peak transmittance is higher than 97% and the durability,stability are both advanced.

Inorganic buffer layers and transparent conductive In2O3:SnO2 (ITO) films were deposited sequentially on flexible polyethylene terephthalate (PET) substrates by ion assisted deposition(IAD)at room temperature. The effects of inorganic buffer layers on the photoelectric properties and bending resistance performance of flexible ITO films were investigated detailedly. The results show that the effects of SiO2,TiO2,Ta2O5 and Al2O3 buffer layers on the sheet resistance,optical transmittance and bending resistance performance of ITO films are different. Adding SiO2 to reduce the sheet resistance of ITO films is the best proposal,of which the reducing rate reaches 29.8%,but adding Al2O3 is inadvisable,of which the reducing rate is only 5.6%;The visible light transmittance of ITO films with Ta2O5 is optimal,of which the average transmittance is over 85%,and the average transmittance of ITO films with SiO2 is above 80%. It is found that the ITO films with SiO2 have better resistance stabilities compared to ones with TiO2 when the ITO films are bent at the same bending radius,but the ITO films with SiO2 have worse resistance stabilities compared to ones with TiO2 when the ITO films are inwards bent at the bending radius of R=0.8 cm and R=1.2 cm.

Tin-doped indium oxide (ITO) conductive thin film is prepared on MgF2 substrate by electron beam evaporation. The effect of oxygen and annealing on the sheet resistance and ultraviolet (UV) transmittance of ITO film is investigated. Furthermore,the properties of ITO film are compared with conventional conductive film substrates Au and Cr. The surface morphological image,sheet resistance,microstructure and transmittance curves in the wave band of 190-800 nm are investigated by optical microscope (OM),four-probe method,high resistance meter,X-ray diffractomer (XRD) and spectrophotometer. Variation range of transmittance is acquired in the wave band of 200-400 nm when the sheet resistance reaches 107 Ω. The results indicate that the sheet resistance of thin film prepared with oxygen is higher than that without oxygen;after annealing the sheet resistance of thin film decreases and the microstructure changes from amorphous to polycrystalline. Compared to Au and Cr,the average transmittance of ITO film with the same sheet resistance of 107 Ω or so,which is prepared with oxygen and annealing,is 10% higher in the wave band of 200-400 nm.