A novel continuously tunable multi-wavelength fiber ring laser is constructed by using semiconductor optical amplifier (SOA) as the gain medium. A Hi-Bi fiber loop mirror (Hi-Bi FLM) is inserted into the cavity as filter. More than 17 stable wavelengths with line-width less than 0.102 nm and more than 25 dB SNR spacing on ITU-grid (100 GHz) are obtained. The output peak power variation of each wavelength is less than 6 dB. These 17 wavelengths can be continuously tuned together within 50 GHz by proper control of the polarization controller of Hi-Bi FLM. The feasibility of using this multiwavelength fiber ring laser in testing the characteristic of erbium-doped fiber amplifier (EDFA) is discussed experimentally.

In this paper,a direct coupling theoretical model in quasi-three-dimension for the gain-wave guide Vertical-Cavity Surface-Emitting Laser (VCSEL) has been created. With the finite-difference method,self-consistent solutions for the injected current density,carrier concentration,optical field and thermal conduction equations are realized to study the characteristics of electrical,optical and thermal fields distribution in VCSEL. A VCSEL with double oxide-confined regions is introduced. The influences of NDBR layers and double oxide-confined regions on the characteristics of VCSEL are analyzed contrastively.The calculation results show that if N-DBR layers are not considered,there must be some errors to the practical VCSEL. The results also indicate that the structure of double oxide-confined regions in VCSEL has been improved greatly the characteristics of lasers,and it provides a method of reducing threshold current and controlling high-order modes.

A simulation model of flashlamp-pumped heat capacity Nd:glass rod lasers is presented. Based on this model,the temperature and stress distributions of heat capacity lasers are studied. It is shown that the Nd doping concerntration and initial temperature affect the stress distribution of heat capacity lasers.The result is useful for the design,safe running and cost-reduction of heat capacity lasers.

The relation between the center of time gravity of the ultrashort pulse and the carrier phase was studied by using three kinds of pulses,named Gauss,Hyperbolic Secant and Lorentz pulses. The analytical expressions of the relation between them was deduced. The results show that the carrier phase affects the center of time gravity of the ultrashort pulse seriously when the pulsed width is shorter than the optical oscillation duration.

The principle of Quantum interference control photocurrent in bulk semiconductors using ejected photo current theory is discussed. A nonlinear interferometric method for diagnosis of phase aberrance of a laser radiation and its second harmonic is described. A scheme of the auto-control system to stabilize the phases of two relative ultrashort laser pulses is presented,playing a key role in the coherent control photocurrent experiments. The experiment result is given to prove the validity of the system,which is fitted either in coherent control or phase aberrance adjusting surrounding.

Using a linear stability analysis method,a linearizing model derived from the nonlinear schroedinger equation is used to analyze the influence of the air gap between slabs on small-scale selffocusing modulation growth in a slab amplifier of a high power laser facility. The quantitative relations between B-integral,the number of slabs,the ratio of air gag interval distance to the thickness of slab,and nonlinear modulation gain spectrum are given explicitly. It is found that as the gap distance increase,the nonlinear gain spectrum moved toward to long spatial wavelength region. The number of slabs also influence the maximum gain value and its spatial frequency. In addition,an approximate expression was given to show the air gap influence by using a gain spectrum without air gap but with an equivalent power and B-integral value.

A 2D finite-difference method is developed to study a Metal-Semiconductor-Metal PhotoDetector (MSM-PD). The time-domain numerical simulation is based on the Poisson equation and continuity equations for electrons and holes. The transient response of the photodector is analyzed. An optimized design of MSM-PD is given to achieve a fast response while keeping a satisfactory responsivity.

Analytic expression with the effect of phase shift on reflection for full width of maximum height of a typical MEMS-based FP cavity is deduced by transfer matrix method. The relationship between full width of maximum height and interference order is simulated with the analytic expression,so does the relationship between full width of maximum height and the gap of the two reflectors. And the result is compared with full width of maximum height without considering phase shift on reflection. The effects on full width of maximum height caused by phase shift on reflection and reflection index respectively are discussed too.

A novel micro high-speed 1×2 magneto-optic switch,which is used in high-speed all-optical communication network,is designed and analyzed. The study of micro high-speed magneto-optic switch mainly involves the optical route and high-speed control technique design. Nanosecond pulsed current transients from nanosecond impulser are used to switch the magnetization of the magneto-optic crystal,which propagates a 1550nm optical beam. The electronic circuits of nanosecond impulser and the pulsed magnetic field design schemes are both simulated on computer and tested by the experiments respectively.The experiment results state that the nanosecond impulser can output the pulse,with rising edge time 1.3～3.2 ns,voltage amplitude 10～90 V and pulse width 4～100 ns. Under the control of MCU singlechip,the optical beam can be stably switched and the switching time is less than 1μs currently.

A device of silicon micromachined Fabry-Perot cavity is introduced. It can be extensive used in the optical fiber communication,such as optical filter and optics attenuator. The device is fabricated by general surface processes,such as LPCVD,RIE,chemical etching and evaporating metal-coating. The silicon nitride film which is suspended above the silicon substrate,is driven by an electrostatic force. The basic principle,operating range and threshold voltage of the device are analyzed,and the factors of influence threshold voltage are discussed. By means of the finite element method,the mechanical,the coupling and the response characteristics of the device are analyzed.

The luminescent properties and fluorescence lifetime of Yb∶YAG crystals with different concentration of Yb3+-doped were studied. Yb3+ ions dopant concentration is 5at%,10at%,20at% amd 30at%,respectively. The absorption coefficients of Yb∶YAG crystals become larger with increasing Yb3+ions concentration. Their fluorescence spectra was measured by using LD with a wavelength of 940 nm as the pumping source and TRIA X550 fluorescence spectrum measurement device. The result indicates that lOat% Yb∶YAG crystals possessed the highest fluorescence intensity at the main luminescence band,1030 nm. Simultaneously,the clearly visible luminescence was observed in Yb∶YAG crystals at 450 nm～680 nm bands,and the intensity of which increases rapidly with the increase of Yb3+ ions dopant concentration.There are concentration quenching phenomenon in Yb∶YAG crystals. This phenomenon was studied,and the decrease of fluorescence lifetime is attributed to up-conversion emission of trace rare-earth ions and cooperative luminescence of the Yb3+ ion.

A solution of a simple and reliable ground detection system is introduced for the rotating mirror system in Image Hyperspectrometer Carried by Satellite in this paper. The hardware of detection system is introduced,its software design scheme,main technologies and design flow are provided in detail.Experiments and application show that the solution works stably and has a good effect.

Photoluminescence (PL) spectra of ZnO nanowires exited with 355nm laser pulse at room temperature were measured. The narrow violet band (peaking at 382 nm) and a broad green band (peaking at 507 nm) were observed in the PL spectrum. The intensity of luminescence depends on the excitation power density and the saturation effect of luminescence was also observed. But the variation and saturation value are different for these two luminescence peaks. It is shown in experiment that the violet peak of ZnO nanowires appear red-shift as excitation power density increases. The mechanism,which includes luminescence peaks appearance,saturation value,luminescence intensity variation,wavelength red-shift,have been analyzed.

Monodisperse,Eu (TTFA)3-doped colloidal SiO2 microspheres with different doping concentrations were synthesized by the modified St?ber method. The transmission electron microscope (TEM) and fluorescence spectrometer were employed to characterize the doping particles. It was found that the particles with the spherical morphology and the smooth surfaces had an average diameter of 300 nm and a size polydispersity of 3.5%. Visible luminescence of Eu3+ from Eu(TTFA)3-doped colloidal SiO2 microspheres was observed,with a lifetime of about 290 μs. Furthermore,the effect of doping concentrations (0.5～1.5wt. %) on the fluorescence intensity and the lifetimes was studied. The results showed that the fluorescence intensity increased with the doping concentrations,there was no obvious luminescence quenching during the processes of being excited,and the luminescence lifetimes were almost invariable while the doping concentrations were changed. Such fluorescence microspheres might have potential in active photonic crystals,microlasers and biological applications.

The white light interferometry for the measurement of low-finesse extrinsic Fabry-Perot interferometer(EFPI) is reported. A broadband light is injected into EFPI,and the reflected light is scanned by another high-finesse tunable Fabry-Perot filter,the periodic spectra of EFPI can be obtained.To measure the cavity length,the spectra are fast Fourier transformed,the absolute length of cavity can be calculated by using the periodic spectra. The measuring accuracy is limited by the length of cavity. The longer cavity has higher measuring accuracy. When the length of cavity are 200 μm,400 μm,and 600 μm respectively,the measured results are agree with the actual length of the cavity.

Based on photoisomerizations and photoinduced alignments of an amorphous copolymer containing azobenzene groups,the writing process of the surface microstructures was studied. Some pattern structures were written on the sample surface by irradiation with two coherent laser beams. The forming mechanism and the polarization selectivity of the microstructure on the polymer surface was discussed by contrasting the phenomenons of azobenzene and di-azobenzene during the experiment.

Nanocrystalline ZnO thin films is a promising material for short-wave laser and luminescence etc,due to its wide band gap (3.37 eV) and high exciton binding energy(60 meV) at room temperature.The high-quality nanocrystalline ZnO thin films is prepared by using sol-gel,grow on quartz glass subtractes,Photoluminescence spectra and Absorption spectra of nanocrystalline ZnO thin films with excitation wavelength 330 nm are measured at room temperature. Two emission bands are observed,one being a strong and narrow ultraviolet emission band its central wavelength is 392 nm and the other being weak and wide green visible band its central wavelength is 519 nm. Crystal structure of samples are examined by X-ray diffraction (XRD) pattern,the mean grain size of nanocrystalline ZnO thin films are calculated by with Debye-Scherrer formula. The results indicate that nanocrystalline ZnO thin films has a hexagonal wurtzite structure and polycrystalline,and showed sharp diffraction peak for ZnO(002),which indicate that as-sputered film were highly c-axis oriented. The grain increases with annealing temperature,Absorption spectra of ZnO thin films indicated that the band gap of the thin films was 3.30 eV.Photoluminescence spectra showed that ZnO thin films emitted strong UV Photoluminescence. The intensities of PL peaks decrease with increasing annealing temperature. In particular the mechanism behind the visible luminescence has also been discussed in this paper. It should be said that the mechanism behind the visible luminescence is still a question to debate. In this paper the visible emission processes of nanocrystalline ZnO. The experiments prove that the luminescence emission peak located 519nm corresponds to the transition from the shallow level of oxygen vacancy to the shallow level of zinc vacancy or electron transition from deep level of oxygen vacancy to valence band.

Both Boltzmann distribution method (BDM) and mean square displacement method (MSDM) are available for the force calibration of non-spherical biological cells in a harmonic optical trap. These two calibration methods were compared with numeric experiments. Results indicate that comparing with MSDM,BDM is not only available for the force calibration of nonspherical or anisotropic cells,but also for irregular cells in optical trap potential with inharmonic and asymmetric profiles. The results agree with the experiments reported.

The fluorescence spectra of whole blood in different disintegration time are measured under the laser excitation. Blood from health small white mice is diluted to different concentration. They are scanned every three hours. The fluorescence spectra of different times are presented. The variety of fluorescence spectra reflect the changes of blood in structure. It is found that the primary emission peaks near 628 nm is significantly red shifted with the time increase and the intensity is weakened in the fluorescence spectra.Based on the experimental results and theoretical analysis,it is concluded the peak red-shifted is mainly due to the theca disintegration of erythrocyte. During the erythrocyte disintegrating,the theca is destroyed in different degree and results in hemolysis. The study may make sense for understand the whole blood disintegrative mechanism.

Continuous spectra transmittance is measured and studied from visible to near infrared bandsusing sun photometer. The atmospheric transmittance is obtained with the solar spectra measured by the accurate calibration sun photometer by Langley method to calculate the irradiance arrive at the top of the atmosphere. From the analyses of different time,aerosol contents,seasons and models,the characters of the atmospheric transmittance are achieved in the sunny,cloud free atmospheric condition. The results can provide the base for target detection out of the atmosphere.

According to feature extraction of high order cumulant,a method is proposed to solve the quantitatively analyzing of five types of gas,where the primary and secondary absorbed peaks are seriously overlapped. The absorbed spectrogram is mapped to four-order cumulant space and detached from each other. A technique is presented based on support vector machine of regularization theory to construct multi-dimension model,and accuracy and iterated rate are improved in small scale samples. The result hints the referenced error is no more than 4%,and satisfied with outfield demands.

Some facts which affect the emulsion contraction during the processing of holographic silver halide plate are analyzed. These facts such as the time of exposure,the temperature of bleaching as well as the dehydration method are studied experimentally. Based on the study,a method of controlling the emulsion contraction which determines the diffraction wavelength of the reflection holography is given and a multicolour holography is attained. The experiment result indicates that a good multicolour holography can be made.

After a systematic description of the principle of tomographic reconstruction system based on Hartmann wavefront sensing,the tomographic reconstruction of circularly symmetric refractive index field is conducted as a static test. The projection data of field is obtained by Hartmann sensor,the reconstruction algorithm is algebraic reconstruction technique and a good reconstruction result is obtained.

A method to generate Single Sideband Return-to-Zero Signal(SSBRZ) is introduced by deriving formulas. One sideband of the generated SSBRZ signal is suppressed more effectively without distortion of the optical pulses. 40Gb/s single channel transmission of Return-to-Zero(RZ) signal,Carrier Suppressed Return-to-Zero(CSRZ) signal and SSBRZ signal over single mode fiber(SMF) are simulated. The results show that SSBRZ is superior to RZ and CSRZ against fiber nonlinearities when chromatic dispersion is completely compensated.

A novel optical etalon based on a strongly chirped sampled Bragg grating is proposed for fiber grating sensing demodulationg system applications. This kind of grating can be produced with proper chirp and sampled distribution parameter. The computer simulation and experimental result is presented.Compared with other conventional etalons,the etalon based on strongly chirped sampled Bragg grating has the advantages of good stability and simple production process,and also is promising for mass production.

A double-pass bi-directional(DP-BD) pump configuration is proposed for the high efficiency Lband ASE. A L-band ASE of 13.7 dBm output power and 38nm bandwidth of 1566～1604 nm where the ASE power intensity is higher than－16 dBm is obtained by selecting 1480 nm LD and heavily doped erbium fiber with optimized length simultaneously. The DP-BD ASE source has a pump conversion efficiency of 23.4% which is larger than that by double-pass forward(DPF) configuration of 11.8%.

A CCD camera system monitoring the photon beam position in synchrotron radiation beam line was described. The system provides the photon beam position related to the entrance slit during beam line operation and maintenance. Several beam lines at National Synchrotron Radiation Laboratory have been equipped with it. 10.53 μm and 2.3 μrad resolutions of the position and angle were calibrated respectively.0.37 mm vertical dithers of the photon beam center was detected,coinstantaneously,showing 8083 μradangular deviations. Meanwhile,it offers the reliable basis for beam line testing and diagnosis of the synchrotron facility.

A small liquid crystal display that acted like a grating and phase-shifting device was used on Ronchi test,to measure a spheric or an aspheric of large wavefront aberration,more quickly and accurately.Instead of a common grating and a step motor,a movable image of grating is shown on the liquid crystal display. This gets rid of the phase-shifting error caused by the motor moving,and the error caused by grating revolve angle not being just 90°. A phase-shifting algorithm is used to test an aspheric,and the wavefront aberration of the aspheric is restored. The experiment shows that a small liquid crystal display can be used a grating and phase-shifting device.

An imaging method to measure the geometrical parameters of contact lens is put forward. In imaging method,contact lens is projected into an enlarged image with a projecting lens. An imaging sensor is used to acquire the enlarged image,and a single board computer is adopted to process the image and to do the calculation of parameters. In addition,a glass ring emerged in the liquid was introduced to hold contact lens without any distortion or dehydration. An example of system is provided. With the system,the thickness t can be measured directly,and fore radius r1 and retral radius r2 can be calculated with the help of h1 and h2 and d2 and d2. With an imaging system of 20 times magnification,and a 512 pixels CCD linear imaging sensor of a 50 μm pixel spacing,the system has a resolution of 5 μm,which is much higher than the accuracy requirement of measurement 0.O1 millimeter.

A new encoding method,which was single ring absolute encoding mode,was put forward by studying the encoding principle of traditional absolute code disc. Based on the designed digit of code disc,the codes that correspond to angle positions were obtained by using VC to program. The pattern was simple and the photolithography technology was easy. The precision of encoder was improved easily and the type of encoder can be made miniature lightly,whose core component is the code disc with the pattern.The method overcame the disadvantage of traditional code disc patterns such as more tracks,complex configuration,difficult photolithography and low encoding precision,and provides theories and technologies of encoding to develop further single ring absolute encoder.

The theoretical analysis of galvanometer scanning system widely using in the technology is described. It's shown that the relationship between the deflection angles of the 2-D galvanometer scanner and the corresponding X-Y coordinates value is nonlinear. A practical method is put forward in the research. Its basic principle is that a correction table is done through comparing the theoretical data with the corresponding data in laser scanning,then the distortion and the others errors are corrected according to a interpolating algorithm. The correction technology is suitable for all 2-D scanning system using two galvanometer scanner,and can correct any laser Rapid Prototyping equipment applying the principle of two galvanometer scanner.

The variable relationship between the threshold of the extrapolation and its correspondent Peak of the Signal-to-Noise Ratio(PSNR) in the Wavelet Bi-linear Interpolation Algorithm is deeply analyzed. The Maximal PSNR Wavelet Bi-linear Interpolation Iterative Algorithm is proposed. This algorithm can automatically search the optimal extrapolation threshold to improve the resolution of the optical remote sensing image without damaging its original information,which makes the detail information of the processed image more favorable to be observed and analyzed. The experiment results show that the PSNR of the image reconstructed by this algorithm is 5.5 dB and 2.5 dB higher than that of those reconstructed by the Bi-linear Interpolation and the Wavelet Scale-Function Interpolation respectively,and its entropy is 1.3 times of its original image. It is an effect algorithm to improve the spatial resolution and entropy of the Optical Remote Sensing Image.

The restoration for 3D(three dimensions) image of wide-field microscope needs to process very large data size,and it spend much time. In this paper,a new method is proposed for 3D image restoration of wide-field microscope based on the BP neural network. The initial step of the method is to transform a 3D image into a series of 2D images. Then,the mapping relationship between the 2D blurring image with defocusing message and 2D clear image is established by training the BP neural network,which has a high ability of learning. Following,every 2D section image of the stack is restored in succession. As a result,the restoration of 3D image of wide-field microscope is achieved. Extensive tests demonstrate that this method has a satisfying restoration effect both in visual impression and quantitative analysis. For adopting small dimensional neural network,the training time is little,and the operational amount is small. Thus,it is possible to realize the real time restoration.

View range is one of the main integrated performance indexes for night view systems,and is also the important performance index needed to give when night view systems leave factory. Finally the performance of night view systems express as view range. So the size of view range directly determines integrated performance of night view systems. Therefore,how to evaluate view range of systems objectively and effectively is the main problem that both producers and users concern. Based on low night level view detection function and image threshold contrast,a new objective view range evaluation method of night view system is proposed in this article with image processing technology,least-square polynomial fitting,vision sense formula under glimmer light circumstance and other knowledge. For validating the method,six groups experimentation with field situation of six kinds' night view system have been finished respectively.The results of experiment indicates that the new method has effectively improved the speed of view range measurement of night view system with good precision and practicability. Therefore,the method has scientific guidance meanings to analyze low night level night view system performance,make technique index sure,improve and develop the night view system performance.

Based on the second-order moment of the power density,the explicit expressions for the beam width and far-field divergence angle of nonparaxial flattened Gaussian(FG) beams are derived. It is found that as w0/λ(waist width-to-wavelength ratio)→0,the far-field divergence angle approaches an asymptotic value of θmax=63.435°,indenpent of the beam order. Then,the nonparaxial Gaussian beam instead of the paraxial one is chosen as the ideal beam,the M2 factor of nonparaxial FG beams is studied and compared with the conventional definition of the M2 factor. In the nonparaxial regime,the M2 factor of nonparaxial FG beams depends not only on the beam order,but also on w0/λ. According to our definition,as w0/λ→0,the M2 factor of nonparaxial FG beams does not equal to zero,but approaches 0.913,0.882 and 0.886 for the beam orders N=1,2,3,respectively. In particular,for N→∞ the M2 factor takes its minimum M2min=0.816.

A two-sphere system with a two-lens zero-power corrector placed behind the secondary mirror was discussed. According to third-order aberration theory,the conditions of the absence of aberrations were analyzed,and the influences to the remaining high order aberrations of the system caused by the change of the relative aperture of the primary mirror,the position of the corrector and the different combination of the positive and negative lens in the corrector were investigated. The results show that the remaining aberrations will increase if the relative aperture of the primary increase or if the corrector approaches the secondary mirror. No matter the first lens of the corrector is positive or negative,there would be a particular optical power which causes smallest remaining aberrations,and it's better to use a negative lens near the secondary mirror.

With the view of obtaining symmetric splitting angle prism,on the basis of Bi-,through designing the orientation of the crystal optic axis rationally,make the prism plane-symmetry about center tangent plane;Resulting in splitting beam symmetrically not only for positive-going light,but also reverse direction light. Namely,two-way symmetrically splitting. Futher studies on the relation between rotation angle of the axis and the structure angle of the prism and wavelength,and analyse the symmetry of the splitting angle when apply the prism designed for 633 nm to other wavelength,the results indicate: the asymmetry degree of splitting angle less than 0.24°,in the spectrum range of±300 nm.

A new method,by which the bubble's size and density of the ship wake can be obtained by using image processing methods,was put forward. With this method,the wake images which are gotten by high speed digital photographic equipments can be processed. The method has characteristics such as visibility,real time and high efficiency,and can be conveniently applied in actual engineering projects.