The damage threshold and morphology of sapphire crystal〈0001〉 have been investigated by nanosecond(ns),picosecond(ps),and femtosecond(fs) laser pulse at 800 nm based on the mechanical,thermal,and photon-electrical properties of sapphire crystal. The star-like crack which is associated with the point group of sapphire crystal is induced by ns laser pulse,and the cross crack induced by ps and linelike crack by fs laser pulse may be relation to the preferred dislocation from anisotropic stain tensor.

Single-shot laser damage of polished MgO(111)surfaces induced by 800 nm pulses at different laser pulse duration was studied by scanning electron microscopy(SEM)and time-resolved measurements of reflectivity. SEM observations after laser irradiation indicated that substantial surface fracture dominated over rapid vaporization. The linear relationship between the ablation area and the logarithm of the pulse energy provided the single-shot ablation threshold. The pump-probe technique was used to investigate the change of the reflectivity during and after laser irradiation. The results showed that the charged particle emission time was about 15 ps. The ablation mechanism was also discussed.

A high-power LD-end-pumped passively Q-switched Nd∶LUVO4 laser at 1.06 μm is reported,with a Cr4+∶YAG crystal as the passively Q-switched component. At the incident pump power of 19.1 W,the maximum average output power of 4.58 W,the shortest pulse width of 84 ns,the highest single pulse energy of 36.6 μJ and the highest peak power of 436.2 W are achieved,respectively.

A diode-pumped passively Q-switched Nd∶YVO4 laser was demonstrated by using GaAs film growing at a low temperature. The threshold power at the Q-switching is 2 W. The shortest pulse duration is 15 ns. The highest single pulse energy is 4.84 μJ and the highest peak power is 330 W. The repetition rate varies between 220 kHz and 360 kHz and the highest average output power is 1.16 W.

Using the different dispersion characteristic of the photonic crystal fiber around different zero dispersion wavelength,the photonic crystal fiber optical parametric amplification was researched with twopump lasers around 780 nm and 1550 nm. Near 780 nm,the impacts of zero dispersion wavelength fluctuations on two-pump photonic crystal fiber optical parametric amplification were investigated,and numerical simulations show that the signal gain bandwidth will vary greatly as the zero dispersion wavelength has a very little change. When the wavelength separation between the two pumps decreased,the impacts of zero dispersion wavelength fluctuations on two-pump photonic crystal fiber optical parametric amplification were restrained to a large extent,but the amplifier bandwidth will have some reduction. Based on this principle,the dispersion flattening optical parametric amplification was designed around 1550 nm. With pump power of 10 W,the gain of fiber optical parametric amplification can reach 65 dB in only 5 m photonic crystal fiber,meanwhile the bandwidth reaches 420 nm,and the gain spectrum is very flattened.

Based on the theory of lasing wavelength red shifting of semiconductor laser due to junction temperature rising in pulsed operation,the time-resolved spectrum was measured by means of scanning optical power during the pulse at different wavelengths with a Boxcar. The thermal relaxation time was calculated by the measured relation of peak moment of optical signal within the pulse varied with wavelength. A pulse semiconductor laser was measured,and the thermal relaxation time was obtained to be 1.2 ms.

An erbium-doped fiber nonlinear coupler(EDFNC),in which the coupling parameters could be controlled by the light were firstly proposed. By using the fusing-elongation machine to fusing together two Er3+-doped fibers,a 3 dB nonlinear coupler was fabricated for the signal light at 1550 nm. When changing the pump light at 980nm launched into one arm of the coupler,the propagation-constant difference between two arms of the coupler would be changed,and then the relative output powers of signal light from two arms would also be changed. Measuring the input pump power and two output signal powers of EDFNC,it obtained the experimental curve of the bar coupling ratio versus the pump power.The experiments showed that when increasing pump power from 0 mW to 20 mW,the variation of coupling ratios could reach to 40%. The theory simulation and the experiment results were well consistent.

The dependence of effective refractive index on polymer fraction of oxidized porous silicon films with various initial porosities and oxidation degree was given by Bruggeman effective medium model. The effective refractive index of oxidized porous silicon inserted polymer PMMA composite films was studied in experiment. It found experimentally that polymer inserted into pores of porous silicon can enhance the stability of optical parameters of the film.

The principle of ultra-rapid-scanning Interferometer is introduced and a new kind of ultra-rapidscanning imaging interferometer based on the principle is provided. The imaging interferometer has a wider angle of field and higher scan efficiency. The character of the imaging interferometer is that it has a rotating planner reflector with an angle of inclination instead of the straight-line planner reflector in Michelson interferometer. The questions of lower scan efficiency and instability are well solved in Michelson interferometer.

By means of using the spectrum tomography combining with the principle of numerical calculation,reconstruction of plasma flow temperature,density,pressure and velocity fields were proposed. Intensity of spectrum line was collected by CCD scanning system of fiber probe. Then,according to relative intensity method,the temperature field was obtained. Using plasma flow physical equations,other parameter fields were gotten. The spatial distribution characteristics of plasma flow temperature,density,pressure velocity field and intrinsic relation of them were completely analyzed.

By analyzing the spectral characteristic of high-voltage corona,an ultraviolet & visible light dualspectrum real-time video image processing and image fusion system to detect the high-voltage corona was proposed. The dual-spectrum system took the high performance digital signal processor TMS320DM642 as a core;light path,the spectrum transformation and image enhancement were designed to capture the ultraviolet signal. They adopted many kinds of considerations design to optimize hardware structural,and fasts fusion algorithms to improve the system speed,and the embedded real-time operating system(DSP/BIOS)to manage multi-process at the same time. Further more,manual registration function that was based on pixels translation was provided. The system can meet the requirement of real-time dual-channel digital image fusion processing in order to detect and locate the high-voltage corona ultraviolet signal in real time. Its merits were speed of response quick,the range coverage was far,not sunlight and drizzle disturbance.

A simple method,immersion plating,used to make SERS-active substrate was reported.Employing AuCl3 Sol,Au nanoparticles were overlaid on the substrate of aluminum plate. SEM image for the Au substrate shows that the shape of Au aurum is island with the average diameter of 80nm. The SERS spectra of pyridine and poly(4-vinylpyridine)molecules on Au substrate were measured. Calculation results indicate that the SERS-active Au substrate made in this way has an enhancement factor of 105. And this substrate is fairly stable after being placed in air for one week.

Terahertz(THz) time domain spectroscopy includes abundant information about the sample,so the image for the structure of the sample can be reconstructed. How to resolve some sample parameters and reconstruct image using phase information and amplitude information of THz wave is investigated. A comparison between phase imaging and amplitude imaging is carried out. The results show: the quality of phase imaging is better than the quality of amplitude imaging if the absorbing of the sample is small;the excursion of the peak brings some effect on phase imaging. The splitting phenomenon of output spectroscopy is found in the experiments,namely THz time domain spectroscopy changes from one peak to two peaks. The analysis shows that this phenomenon results from abrupt change of the thickness or refractive index. This phenomenon can be used to study outline imaging in Thz field.

The theoretical analysis based on Rayleigy-Enhanced nondegenerate four wave mixing provides the closed-form solution for the signal. The temporal behavior of the RENDFWM has been investigated which reveals the characteristics of driven exciting resulted from material response to optical field. The resonant signal shows asymmetric temporal behavior and oscillation structure when τ＜0.

Dynamical behaviours of a single-mode laser Haken-Lorenz system were investigated.The steady state solution of the system was obtained. Stability analysis was given by using the principle of linear stability. Characteristic equation was gotten and Hopf bifurcation point μc was determined. A periodic oscillation analytic solution for the system at bifurcation point was obtained by using the method of series. The dynamical behaviors of the system were given by computer numerical simulation. The results show that when the bifurcation parameterμ crosses the critical value μc and Haken-Lorenz system gives rise to limit cycle,i. e. periodic oscillation solution,the result accords with the analytic one.

The rules of quartz crystal that the refractive index varies with the wavelength at different temperature are studied. With strict solution,the expression about the coefficient of Sellmeier equation is gained,and the refractive indices corresponding to different wavelength are calculated,they are consistent with the experimental results . The expression of the thermal refractive index coefficients at different wavelength are gotten by curve-fitting means,and the thermal refractive index coefficients at different wavelength are calculated. Then the constants of the Sellmeier equation at different temperature are gained,so a method of doing the refractive indices of quartz crystal at different temperature and different wavelength is got.

The Zn2+-doped nanocrystalline anatase-type TiO2 film electrodes were prepared by sol-gel method. The photoelectric properties of the electrodes with different concentration of Zn2+ were studied by photocurrent action spectra and current-potential (I-U) curves. According to the action spectra,the concentration of Zn2+ can affect the photocurrent magnitude remarkably and its optimum is dependent on the particle-size of T1O2. Illuminated by 320 nm monochromatic light,Zn2+-doped TiO2 film electrode with the concentration of 0.1 mol% produced the largest photocurrent which increased 40% compared with which produced by undoped electrode. The I-U curves show that the conversion from anodic current to cathodic current occurs in all illuminated TiO2 film electrodes during the potential dropping from 1.OV to －0.4V,and the onset potential of anodic current was affected by the concentration of Zn2+. In the region of cathodic potential,in addition,similar cathodic dark current was observed for each electrode and it increased rapidly with a dropping potential.

Actual ultra thin multilayers are difficult to have a clear-cut interface due to interface interdiffusion. It is assumed that ultra thin Multilayers have a periodic graded-index multilayer structure.A line model and a cosine model are used to simulate soft X-ray reflectivity of periodic graded-index multilayers. The simulations show that periodic graded-index multilayers with cosine model have a higher reflectivity. it's significative for design of ultra thin Multilayers.

13～20 nm monolayer high quality GaAs thin films have been deposited by radio frequency (RF) magnetron sputtering technique in the atmosphere with hydrogen. The effect of hydrogen passivation on the micro-structure and optical properties of GaAs films was reported. The GaAs thin films were studied by X-ray diffraction,atomic force microscope pattern,absorption and photoluminescence (PL) spectrum.Experimental results show that the GaAs thin films have fcc zinc-blende structure,larger the granular size and more coarseness morphology,when the substrate temperature is at 500℃～520℃ with hydrogen or at 520℃ without hydrogen,a clear exciton hump and blue shift phenomenon were observed in the absorption spectra as well as a stronger peak were found in the PL spectra. These results indicate that hydrogen has passivation effect on GaAs thin films significantly.

A new approach for packed FBG(fiber Bragg grating) pressure sensor using chemical bonding technics between polymer and FBG was proposed and demonstrated. A kind of chemical bonding material was used to strengthen the bonding between fiber and polymer in order to improve the pressure response of FBG sensor. This technics resolved the problem of avulsion in high pressure due to the big difference elastic modulus between polymer and fiber. The experimental result indicated that,within 0.04 MPa～0.6 MPa,the pressure response sensitivity was －4.48 nm/MPa and the resolution pressure measurement was ±0.01 MPa,which is 1463 times higher than that of the bare FBG. . The linearity of the temperature response curves is 0.9978.Reflection spectrum showed a steady figure through repeated measurement.

By the way of computer simulation,the influence of bias angle of Faraday mirror upon polarization state of output light of Faraday Mirror-typed Optical Current Transformer is analyzed using the theory of Jones Matrix. The value of actual bias angle of Faraday mirror and the effect of out magnetic field upon bias angle of Faraday mirror are measured by experimentally. Existence and changes of out magnetic field cause bias angle of Faraday mirror deviating initial value and output light of system degenerating into elliptical polarization light from ideal linear polarization light. It brings the decline of sensitivity and stability of FMOCT. At the same time solving the influence of out magnetic field by electromagnetic shield is proposed.

A semiconductor absorption fiber-optic temperature sensor was designed for aircraft. The sensor was based on the temperature dependence of the band edge absorption of infrared light in GaAs semiconductor platelets. The sensor used GaAs chip as the sensitive element of temperature,and the optical fiber was medium of transmitted light,and the diode is the light source,and the triode is a transducer of photo-electricity. The twin-channel compensative measure system can eliminate the influence of light source fluctuation. In addition,the temperature sensor had many more advantages such as small in volume,simple in structure,high in sensitivity and resisting strong electromagnetic interference. According to the experiment,the sensor has accuracy of 0.1℃ over a temperature rang from-20℃ to 85℃. It was suitable for measuring the environment temperature of the aircraft in strong electromagnetic interference. It was the base of achieving the temperature measurement further in optic transmission and craft controlling system.

The self-diffraction characteristics of bacteriorhodopsin(bR) film illuminated by weak light were studied. The model describing the distribution of the light intensity of the amplitude grating induced by interference light in bR film under weak light was given,and the distribution of the transmitted light intensity y from the amplitude grating was described approximately as ysinax,which was in agreement with the experiment. The relationship between y and α was obtained,which indicated that giveing the wavelength of incident light,the weaker the incident light intensity would become,the bigger a would get.When the incident light intensity was 0.072/T(mW/cm2),α equaled to 1.From different incident intensities and incident angles,the self-diffraction efficiencies were calculated,from which it could be found that the optimal incident angle was 2° corresponding to the maximum diffraction efficiency.

The peak value and Full Width at Half Maximum(FWHM) of scattered light's spatial spectrum intensity distribution of air bubbles in water can be used to determine bubbles'size and density. By the developed air bubbles producing setup and scattered light's spatial spectrum intensity measuring and analyzing system,how detecting distance affects backward scattered light's spatial spectrum intensity was investigated experimentally. The experiment results show that as air bubbles'size and density are invariable,the change of detecting distance has different effect on the peak value and the FWHM of scattered light's spatial spectrum intensity distribution under different illuminations. The peak value and the FWHM of scattered light's spatial spectrum intensity distribution are unchanging as the detecting distance increases under expanded beam illumination,for the number of bubbles scattering light increases constantly,which can offset scattered light intensity's losing caused by a longer distance propagation. But the.peak value reduces gradually and FWHM increases as the detecting distance increases under the slim beam illumination. The experiment results also show at slim beam illumination has advantage for long distance detecting.

A fast algorithm is introduced to increase the speed of hidden surface removal,based on the spatial resolution of human eye. A hologram is divided into several regions according to different viewing position. Then,the data of scenes are obtained for every region by removing hidden surfaces corresponding to center point of the region. The operation of hidden surface removal is performed only once for one region instead of being performed for every sample in the region. The effects of removing hidden surfaces corresponding to center point of a region and which corresponding to every sample are the same for human eye,if the size of region is small enough. But the speed is accelerated greatly. The experimental results reveal that the speed of hidden surface removal is increased about 105 times. On the other hand,the quality of reconstructed image doesn't decrease.

Spatially partially incoherent and coherent dark photovoltaic solitons are comprehensively experimentally studied with phase masks in LiNbO3∶Fe crystals. One-dimension and two-dimension dark photovoltaic solitons are observed with spatially partially incoherent and coherent beam,which result from the bulk photovoltaic effect and when diffraction is exactly balanced by photorefractive self-defocusing. The analysis of theory and experiments shows that dark photovoltaic solitons depend on the direction of propagation,orientation of the intensity gradient,with respect to the crystalline axes of the medium. Under certain conditions,the steady-state spatially partially incoherent dark photovoltaic solitons can be observed.

A flexible scheme for all-optical packet header and payload separating using two SOAbased Mach-Zehnder interferometers(SOA-MZIs),one for header extraction and the other for payload extraction was proposed. In addition,the scheme,by changing configuration,was applicable for processing optical packets of different lengths and bit-rates. Through numerical simulations,an intensity contrast ratio of more than 16dB for both header and payload at 50Gb/s can be achieved.

By theoretic analysis of the interleaved sampled fiber Bragg gratings (ISFBG),the refractive index modulation expression of the ISFBG is deduced. It shows that the ISFBG can be equivalent to a conventional sample fiber Bragg grating. The interleaving technique makes it available that low refractive index modulation results in more channels with almost identical reflectivity. For the first time,two SFBG are interleaved in a fiber and a 10-channels dispersion compensator is fabricated with almost identical reflectivity. The group time delay ripples of each channel are almost less than 20 ps.

An edge router for hybrid optical switching network which mixed OBS and OCS together was designed and implemented in the experimental system. The switching method (OBS or OCS) in the hybrid network can be selected by the service requirement. The result of the experiment shows that the data rate is relatively higher in OCS way,while the network bandwidth is better utilized in OBS way. By mixing these two switching ways together,the flexibility and adaptability of the network can be improved to a certain extent.

The mathematical model of optical packet switching architecture based on feedback FDL contention resolution is stablished and analyzed. The priority of the packets from FDLs is higher than those from input fibers in this model. The formulation of packet loss probability is deduced through neglecting the degradation of optical signal and the crosstalk in optical switch matrix. The packet loss probability is lower in low load than in high load. This is due to the nonlinear distribution of the probability of arriving packet from feedback FDL vs the load. With the increment of the load,the probability of arriving packet increases very slowly in low load and very fastly in high load. There exists no limit in packet loss probability by adding the number of FDL to improve the performance. The characteristic is different from the contention resoluton based on wavelength conversion that exits a limit. It will be very useful to comine wavelength conversion and FDL to break through the limit.

A laser-based multimode detector is introduced. To gain the optimal detection,the optical configuration is designed and optimized. Based on the theoretical analysis,mathematical deduction and Matlab simulation,the optimum numerical range of the parameters of the optical configuration are obtained. In the thermal lens detection mode,generally,smaller waist radius induces stronger the thermal lens effect,on the other hand,the waist radius of the probe beam,the distance between the waist and the sample and the distance between the waist and the detecting plane synthetically determine the intensity of the acquired signal. In the retroreflected detection mode,the focus length of the focusing lens has to be short enough,and the distance between the lens and the capillary,which has to be less,influences the detection a lot,while the lens has to be far enough both from the laser source and the detection plane.Finally,the thermal lens impacts the retroreflected interference unapparently. To eliminate the influence strictly,a proper little distance to shift the two detecting channels can be adopted.

In order to determination fixed optical path difference of wind imaging interferometer,the principle of wind field measurement is described. The factors which influence on fixed optical path difference are analyzed. Three requirements including visibility,phase and near spectral lines in phase for WINDII(Wind Imaging Interferometer)are analyzed respectively and obtain quantificational relations between them and fixed optical path difference. Three conditions are considered together and conclude the selective principle of fixed optical path difference. At last the theory is applied to other wind imaging interferometers and proves their fixed path differences.

A sparse-aperture design named dual three sub-apertures,which is composed of nine subapertures,is proposed. Each three sub-apertures make up of a sub-pupil,three sub-pupils make up of a main pupil. The configuration of dual three sub-apertures is symmetrical and redundant. The symmetrical sparse－aperture systems of three arms and dual three sub-apertures are researched. The feature and Modulation Transfer function(MTF) are compared between dual three sub-apertures' and three arms'.Image simulation and Wiener filter of the two kinds of symmetrical sparse apertures are illuminated with different fill factors,and image quality is evaluated. The nonredundant sparse aperture of Golay6 is also compared. The results show that the configuration and image quality of dual three sub-aertures are better than three arms'. The symmetrical configuration of sparse aperture systems has the advantages of flexible configuration and easy fabrication.

SAR and optical image fusion was performed using wavelet transforms with different decomposition schemes and wavelet basis. The characteristics of different wavelet transforms were considered. The performance of fusing results were compared and analyzed. Considering the conducted experiment and computational complexity,according to different applications,recommendations on choosing a particular wavelet transform to produce satisfactory fusion result in SAR and optical image fusion in different applications were given.

A real-time digital image stabilization system was presented，which was based on the gray projection algorithm. It demonstrates the application of gray projection algorithm in the field of digital image stabilization,as well as the algorithm optimizations of median filter,region selection and referenced frame selection in image stabilization system. The hardware of this system consists of vibration platform,optical lens,CCD,A/D card and computer. The software programming is implemented in Visual C++ programming environment on the DirectShow platform. Through quantitative analysis and evaluation,the result of image stabilization test shows the convenient,quick and accurate characteristics of gray projection algorithm. Also,it demonstrates itself as a feasible approach for real-time digital stabilization of cameras.

The imaging characteristics of spacial transient optical signal are introduced. A digital image processing method based on the high-speed Digital Signal Processor for spacial transient optical signal locating is proposed in this paper. The image processing procedure includes filtrating the background and weak noises by threshold segmentation,removing the strong noises by target recognition based on the continuity of target signal and calculating the centroid of target signal at last. Experiment results show that processing speed and measurement accuracy of this method are high,and can satisfy the request of locating system.

Aiming at the problem of complexity and inflexibility of image sampling control in the video image collection technology today,a method of realizing I2C bus interface by VHDL technology is proposed in this paper. This method based on the available video sampling chip SAA7111 can be used for control video collection processor to collect video image. The experiment indicates that I2C bus can control SAA7111 to sample image data correctly and steadily. This scheme is well transplantable.