The Double-Temperature Equation(DTE)was simulated with the finite difference method,which was formatted simply. The effect of the pulse shape on the ablation results had been studied when the femtosecond laser was irradiated on the copper surface. The simulation results show that if the laser pulse energy is not changed,the effect of the laser shape will be ignored. And if there are several laser pulses irradiated on the material,the thermal incubation effect would occur only when the repetition rate is in a scale(which is changed with the character of the materials). For the materials that have good conductivity,such as metals,the thermal incubation effect is not clear. Experiments show the same results.

The periodically poled LiTaO3 frequency-doubling the broad-band and quasi-cw laser of seeded Ytterbium-doped double-clad fiber amplifier have been investigated experimentally and theoretically. PPLT is 40 mm long and 7.67 μm in period. The central wavelength of fundamental laser is 1.064 μm and 6 nm in bandwidth. Applying the quasi-phase matching theory and the character of fundamental laser spectrum,the relation of second harmonic power with the temperation was explained. The frequency-doubling efficiency of 1.8% is obtained when the broad band laser power is 2.2 W.

The temperature characteristics of 808 nm InGaAsP-InP SQW lasers have been investigated in a heat-tight system by analyzing their structure. It is shown that the power and the slope efficiency of the devices decreases from 1.74 m to 0.51 W and 1.08 mW/mA to 0.51 mW/mA in the temperature range of 23～70℃,respectively. Lasing wavelength shift coefficient dλ/dT is 0.44 nm/(℃). The characteristic temperature T0 of 325 K is experimentally obtained. The thermal resistance of the chip,determined experimentally,is 3.33℃/W.

The relationship between the two thresholds of inversion density in Q-switched laser,high Q value threshold and low Q value threshold is acquired. Through analyzing the relationship between pulse width and population inversion density and the relationship between diffraction efficiency and population inversion density,a conclusion is obtained that the pulse compression is gotten by increasing pumping rate only when diffraction efficiency is matched up to pumping rate and repetitive frequency in A-O Q-switched laser. And the matching formula between diffraction efficiency and pumping rate is acquired by the match condition. The diffraction efficiency in the formula is just the minimum one to effectively compress the pulse. The theoretical results are verified by the experiments.

The modal threshold gain of cylindrical and oxide-confined vertical-cavity surface-emitting laser (VCSEL) with potential applications in optical communication and optical interconnect,is simulated numerically by using Vectorial Field Model. To weaken the parasitic reflections from the shell(perfectly conducting metal cylinder),more practically,it is considered the shell as non-perfect conducting one,or moreover,it is supposed that the shell is separated from the laser. The threshold gain versus pair number of top Bragg mirror in the two situations is compared with that in the case of perfectly conducting metal cylinder. The result shows that the threshold gain curves are similar for high-order Bessel modes,and they are quite distinct for O-order Bessel modes.

One of the major tasks for the ultrasound generated by laser is the discussion of the two regimes: thermoelastic regime and ablation regime,and each of the theoretical directivity patterns are mentioned. Based on the effect of array factor,a newly method of the laser ultrasonic generated by a phased array of laser beams was proposed. This means,a method to make the ultrasound field be steered and amplified in a particular direction,can be designed and implemented to enhance the signal propagation in the region of interest. It will be more significant to apply ultrasound generated by this method in nondestructive testing of materials and products. The corresponding system has been completed in practice.

The Bragg matching and the uniformity of Bragg diffraction efficiencies of multiple volume holographic gratings(MVHGs),which were used for wavelength demultiplexing devices in optical communication based on all wave optical fiber,were theoretically studied and quantitatively analyzed. It was shown that the Bragg mismatching would be caused due to the recording medium dispersion during wavelength demultiplexing with wide spectra by employing MVHGs. Moreover the Bragg diffraction efficiencies of MVHGs with homogeneous refractive index modulation obtained at short writing wavelength would not be uniform at different optical communication wavelengths. And it has been experimentally demonstrated. For this reason,the improved dependence of writing angles on communication wavelengths for fabricating angle-multiplexing transmission MVHGs and the corrected formula for refractive index modulation of individual MVHG at writing wavelength were presented in order to ensure rigorous Bragg matching and the uniformity of diffraction efficiencies.

Based on a coupled-mode theory,the power transfer among many parallel single-mode optical fibers formed into“--” has been investigated. The analysis shows that the distance between each of the N fiber centers has an effect on the coupling coefficient and power transfer. The solution of the coupled equation for three parallel single-mode optical fibers has been given,and is comparatively studied for different initial conditions. Numerical simulations show that power transfer will be periodical when coupling occur among many parallel single-mode optical fibers formed into“--”.

The electric field distributions of electro-optic deflectors with several different electrodes was studies by the finite element method. A new deflector with hypersurface electrode structure and bigger deflection angle is designed. Compared with the deflectors based on cylindrical electrode structure and hyperboloid electrode structure,it is shown that the new designed electro-optic deflector has bigger deflection angle and higher linearity of electric field gradient.

A novel LiNbO3 modulator based on Si2N2O substrate is proposed. Using the finite element method,the proposed modulator has been analyzed. The optimum structure parameters of the novel modulator are obtained. The modulator operates with a 3 dB optical bandwidth of 120 GHz,a half-wave driving voltage of 3.5 V,and characteristic impedance of 50.32Ω. The results show that broad bandwidth and low half-wave voltage can be achieved simultaneously. It is a promising candidate for future ultra-high-speed optical fiber transmission system.

A volume reconstruction approach of emission spectra was proposed,whose three dimensional reconstruction performance was studied by numerical simulation. Results show that this new algorithm has faster convergence velocity and higher precision compared with common used approaches and a three dimensional single-peak phantom was reconstructed precisely only with two projection angels. An arc plasma temperature distribution was also obtained in our application experiment of this approach.

The absorption,emission,excitation and phonon-side band spectra of Eu3+ doped in 1mol(60-χ)Bi2O3-χTeO2-30B2O3-10ZnO(χ=5,10,20,30,molar percent) were measured. The Ω2 and Ω4 parameters of Eu3+ for optical transition were calculated from their emission spectra in terms of reduced matrix U(t)(λ=2,4,6) character for optical transitions. The results indicate that the intensity parameters Ω2 decrease as the increase of Bi2O3 and decrease of TeO2 contents. It suggests that the symmetry becomes higher,the bands of Eu and O atoms become weaker and the covalency of Eu and O atoms decreases. In the meantime,the electron-phonon coupling becomes weaker and the thermal stability of the glasses enhance obviously as the increase of Bi2O3 and decrease of TeO2.

The absorption induced by intersubband transition in semiconductor superlattice was studied.Numerical illustrations of the optical absorption in a GaAs/AlxGa1－xAs superlattice were given. The optical absorption coefficient as a function of the incident optical frequency,the optical intensity,the temperature and the structure parameters of superlattices(The width of quantum well,the barrier width and the composition percent of Al) were obtained. The simulation results showed that the absorption spectra of superlttice appeared as asymmetric absorption band. The optical intensity only changed the magnitude of absorption coefficient. The structure parameters of superlattice could change the width of absorption spectra and the resonant photon energy. The wider the well or barrier were,the narrower the absorption band became the smaller the center absorption band,the bigger was the absorption coefficients,and the absorption peak red shifted. The absorption band became narrow and the absorption coefficients increased when the composition percent of Al increased.

The novel parallel-aligned liquid crystal spatial light modulator(LC SLM)is introduced,which is designed to operate at phase-only mode for wavefront correction. The optical characteristics characteristics of the LC SLM were measured and analyzed theoretically. The PV(Peak Valley)value of 0.07049λ(λ=0.6328 μm)after correction on the area of 1 cm2 was obtained with our phase-only LC SLM.And Strehl ratio of 0.989 in our experiment indicates the approximate upper limit of the ability of LC SLM to correct a aberrated wavefront when it is used in adaptive optical system.

For electromagnetic plane wave propagating in nonlinear left-handed material,the properties of nonlinear TE surface waves localized at the interface of a left-handed material(an interface separating a left-handed material and a right-handed material or an interface separating two left-handed materials) are investigated in detail. The results of frequency characteristics prove there exist both passband(s) and stopband(s),which have the wave power-dependent properties and can be controlled by varying the power in the waveguide. The frequency dispersion and variation of group velocity with frequency are also calculated. Base on the analysis,the interface between a nonlinear left-handed material and a right-handed material can support both forward TE surface waves and backward TE surface waves under certain conditions. Whereas,the relative properties are quite different when the surface waves localize at the interface between two left-handed materials,there only can exist backward waves according to certain conditions.

The transmission properties of one-dimensional metallodielectric photonic crystals are studied theoretically. The matrix transfer method is used to numerically simulate the transmission through the structure. The result shows that transmission resonances can increase the transmission dramatically and reduce the absorption in a certain extent. By selecting the thickness of Au and MgF2 layers and the periods number properly,a pass band whose transmission is above 0.4 in the visible range is obtained and light can hardly pass the structure in other frequency ranges. The structure has high transmission and metal's ad-vantages,so it can be used in many fields as sensor,eye protection devices,heat reflecting windows and liquid crystal displays.

Based on dual-wavlength action and sum-frequency-mixing theory,a series of optical thin film for LD pumped Nd∶YAG crystal,LBO intracavity sum-frequency-mixing 500.8 nm laser are designed and manufactured. To obtain optimum output power,the coating design of resonator mirror is analysized. The method that adjusts one resonator facet reflectivity for fundament laser by fixing the other resonator facet reflectivity is used,by computer thin film optimization methods based on the reasonable starting desing.The dielectric high reflective laser mirror for 500.8 nm laser is achieved by double ion beam sputter technique,which is controlled by a time-power monitoring method. An optimized CW 500.8 nm laser at room temperature is obtained for the first time in China. The maximum laser output power of 20 mW is obtained when a incident pump laser of 1.8 W is used.

Diffraction efficiency and laser induced damage threshold relay on the optical character,and the laser induced damage character and mechanical character of multiplayer dielectric gratings(MDG) are used in Chirped-pulse amplification. A multi-layer dielectric stack design used at 1053 nm and exposed at 413 nm is given. The analysis show that H3L(H2L)^9H0.5L2.03H meets the requirement of MDG. At last,the optical character of the sample is tested. There is a good agreement between the test of transmittance curve and the design. Laser induced damage thresholds are 14.14 J/cm2 and 9.32 J/cm2 respectively when laser incident vertically and 51.2°. The multi-layer dielectric used in MDG represents compression stress force.

Design of a wide-angle off-axis optical see-through helmet-mounted display(HMD)becomes a challenge since its weight and size are constrained by human factors. Diffractive optics has the potential to play a key role in several areas of head-mounted display. They can reduce size and weight while providing some unique functions that would be difficult to implement with conventional refractive optics. A 60°-diagonal field-of-view,wide spectral band hybrid diffractive refractive see-through HMD using off-axis optics is proposed. It possesses a 10mm exit pupil diameter and a 22mm eye relief,and satisfies the requirements of human factors. In addition,the chromatic aberration is only 14μm,and the whole optical system is suitable for a 15mm-diagonal color liquid crystal display(LCD) with SVGA resolution.

A pair of reflective fly eye lens with a high brightness LED as light source is put forward for micro-display projector. Because of reflective system,the embodiment is shorter than 20 mm. The uniformity is above 80% and the efficiency of the illuminator is better than 75%. The design method with induced equations for calculating the lens surface is given. Computer simulated results are also presented.

A new type of corrosion sensor for reinforcing steel was developed in this paper. The optical fiber grating was pre-strained when it was fixed on the surface of cylindrate steel bar. The strain would be released when the steel was eroded,the wavelength of FBG will be changed accordingly. The corrosion depth could be measured by detecting the wavelength of fiber grating. The precision was better than 0.1 μm and the measuring depth scope of 12 μm could be obtained. The sensor could be used to monitor the early corrosion of reinforcing steel in concrete structure.

Based on the theoretical analyses of the magneto-optical properties of a Bi4Ge3O12(BGO) crystal,the Verdet constants of a BGO crystal at different wavelengths are measured employing the double frequency method. And the experimental results agree with the theoretical value. Combine the measured absorption coefficients with the relations between the Verdet constant and the light wavelengths,the magneto-optical figure of merit of the BGO crystal is presented. Additionally,the magneto-optical properties of a BGO crystal are compared with that of some magneto-optical materials usually used for optical fiber current sensor. The results show that BGO crystal is more suitable for fabricating optical fiber current sensors.

A novel FBG sensor based on spoke-structure pressure box by utilizing FBG as the element sensing component is presented. Under room temperature,within the range of 0～30KN,its linearity and sensitivity reaches 99.91% and 22 N,respectively. Furthermore,it has excellent repeatability and high response speed. Compared with other FBG sensors,the spoke FBG sensor has wider measurement range and higher interference resistance. In addition,owing to its applicability for WDM systems,sensing networks can be constructed by FBG sensor to measure multi-point and many physical parameters. This research demonstrates that the designed sensing system has the advantages of simple and compact structure,easiness for manufacture,little delay time,good repeatability,light weight,etc. And it will have various applications in the fields of monitoring large buildings such as bridges,mansions and mass scale tunnels.

The dispersion properties of photonic crystal fibers(PCFs) with hybrid cores were systematically investigated by using plane-wave expansion method. The numerical calculation results show that an ultraflattened dispersion range of more than 800 nm in which the variation of dispersion is less than 0.6 ps·km－1·nm－1 can be achieved at～1.55 μm by properly designing the structure parameters of the PCFs.

The electro-optic effect and the field distribution of Lead lanthanum zirconate titanate(PLZT)transparent ferroelectric ceramic waveplates are reviewed. The feedback single rotatable-variable PLZT waveplate polarization controller is constructed based on the variable retardation and rotatable axes of a PLZT waveplate. For this controller the simulated annealing algorithm is applied to dither optimization considering the limit of phase shift and the endless rotatable axes. Simulated research results show that this controller can transform any varying general input polarization state into an arbitrary linear output polarization state and in the desired direction more than 98% of total light intensity is attained. On controlling the phase shift can vary within 0～2π,so the fluctuation caused by resetting can be avoided.

High-Speed double-edged Wavelength Interrogation Technology for fiber Bragg grating sensor array was proposed,which employed the logarithm of the output ratio between the adjacent two channel of arrayed waveguide grating to determine the measured wavelength. This system permitted a fast and simultaneous interrogation of multiple wavelengths without any mechanically moving parts. The thesis mainly demonstrated the feasibility of this interrogation project in theory and experiment.

In the polarization mode dispersion(PMD) compensation experiment,the degree of polarization (DOP) is used as the most common feedback signal,which reflects PMD and its influence on the transmission system factually. The influences of first-order and second-order PMD on DOP of four optical modulation formats(RZ,CSRZ,RZ-DPSK and CSRZ-DPSK) are compared and mathematically analyzed.The result shows that different formats have different DOP and the second-order PMD has less influence on DOP of CSRZ-DPSK format,which is fitter for mitigating PMD than the other formats in self-adaptive PMD compensation system.

It is used attenuated laser pulses as the signal source rather than single photons in practical QKD system. The channels is used to transmit are lossy. Eve's eavesdropping ability is limited. On the basis of above three points,a eavesdropping device is presented. Meanwhile,the study is analyzed the calculation of the effective average Alice/Eve mutual information and Alice/Bob error rate's upper limit in six states QKD protocol. It shows that Breidbart eavesdropping/beamsplitter is the more effective one compared with Breidbart eavesdropping(B/B strategy).

The detection accuracy will be reduced due to the disturbance of noise and outside to original data. It is necessary to apply the band-pass filter in the wavefront power spectral density(PSD) analysis to handle this problem. The effective filter can reduce the effect of outside band noise and avoid frequency aliasing. The infinited impulse response band-pass filter(IIR) and the finited impulse response band-pass filter(FIR) were designed in this experiment. Characters of the two filters were compared by simulating analyse. And the result indicates that the better evaluation would be obtained if the FIR filter is used in the wavefront PSD which is used in testing large aperture components.

Using the wave coupling theory of the linear electro-optic effect,a new method to measure mini rotating-angle is developed,which is with high precision. According to the wave coupling theory of linear electrooptic effect,advanced by W. L. She et al.. The relation between the output intensity and the incident angle is formulated. That is to say,the displacement of the incident angle could be determined accurately by measuring the output intensity. Based on this principle,a simple system was presented to measure the small rotating-angle of an object,meanwhile,its measurement range and accuracy could be modulated by changing the external electric field or the wave length of incidence. Its measuring accuracy can be 3.5 within the measurement range of 3′ when the electro-optic crystal is LiNbO3.

To essentially eliminate the measuremental errors arisen from light source power and wavelength fluctuation,a measurement method of solution concentration by means of glancing incidence was proposed.The method is based on the relationship between solution concentration and the refraction angle of the medium transparent. Such a measurement system was developed. The relationship between critical light of refraction angle and the concentration was analyzed,introducing the structure of measurement system,and the researching of measured precision and practical. The system to measuring solution concentration of standard,the test data go to regression and demarcate. A mathematical formula is based on the relationship between solution concentration and refraction angle. Different concentrations of a set of sucrose solution,with the concentration being from 5% to 80%,were measured experimentally. The maximum absolute measurement bias is no more than 0.003%. Tests show this system prospectively with practical applications of engineering.

There are several different sources of thermal energy acting on a spacecraft as it flying on heat dreariness orbit;solar radiation,albedo,earth emitted infrared,and heat generated by camera equipment itself. Temperature fluctuating is a bad influence on imaging quality of high resolution camera. Purpose of thermal control is to maintain all the components of a spacebased camera within their respective temperature limits. Detailed thermal analysis and temperature calculation in different work status is put in practice on a spacebased high resolution camera as a whole in the paper,the result can supply references to thermal control for spacebased high resolution camera.

Automatic lighting control systems which is controlled by motorial control boards and executed by harmonizing alterable diaphragm with electronic shutter in High-Speed TV Measure Instrument is incroduced. In this way,it would widen system's dynamic range of adjusting light. Adopting get feedback signal conbined average gray with peak gray,adaptability of automatic lighting control systems can be effectively solved in diversified background. Putting forward arithmetic base on Quadratic Function to calculate feedback quantity,Convergent Velocity during lighting can be improved and smaller overflow of the system can be insured.

An X-ray detector project,based on the narrow CsI(Tl) scintillating crystal and area-array CCD,using fiber optic and fiber optic plate as light coupled and transmission with fan-beam linear array scanning,has been put forth in this paper. Below 450 keV for x-ray energy,on the base of the physical analyzing and mathematical modeling,the luminescent efficiency property of narrow CsI(Tl)scintillation crystal has been studied by using Matlab. While the parameters of μph、μc、R、Rs、and σ equal to 0.00313,0.0000295,0.95,0.8,and 0.000222 μm－1respectively,it is concluded that the length range of the narrow CsI(Tl) scintillation crystal is 926～4512 μm,the height range is 242～5000 μm,and the width is 242～5000 μm. In the range of the above size,it can be obtained that space(or geometry) resolution of the narrow CsI(Tl) scintillation crystal is better and luminescent efficiency is also the highest.

Using the electrochemical polymerization dye sensitization(ECDS) method,Polyaniline(PAn) which is used as top region material in solar cells is sensitized with direct blue dye(DS),and sensitized Al grid/DS-PAn/n-Si/Al heterojunction solar cell is prepared by ECDS. Influences of the ECDS on the absorption spectrum and the junction characteristics of the solar cell were discussed and output characteristics were measured. The results show: the absorption spectrum of the sensitized PAn films is much wider and stronger in vis-range;the diode quality factor is about 6.3 and the height of latent barrier potential of p-n junction is 0.89 eV;the short-circuit current and the conversion efficiency of sensitized DS PAn/Si heterojunction solar cells are greatly improved,which the short-circuit current can increase about 6 times,the fill factor is 57% and the efficiency can reach 1.42% under the illumination of 37.2 W/m2,respectively.

Starting from the propagation equation of the cross-spectral density matrix,a detailed study of the focal shift and focal shift of polychromatic vector Gaussian Schell-model beams passing through a system with the aperture and lens separated is performed. It is shown that before inserting a polarizer the focal shift appears,there is no focal switch,and after inserting the polarizer the focal switch can take place.By rotating the polarization angle the behavior of the focal switch can be controlled.

A model of three-beam interference has been set up to explain the observed beam patterns which are generated by Gaussian beam passing through an axicon. The mathematical simulation is based on interferential theory,and the effect of the vertex of the axicon. is also considered. The derived equation for describing the transverse intensity distribution gives good approximation to the experimental result as well as the zero-order Bessel function. This beam is characteristic of non-diffraction and can be used to study the newly-type optical tweezers.

Using Kogelnik's equation of diffraction efficiency of monochrome light from thick hologram gratings,an expression for calculating the diffraction intensity spectrum of a photorefractive volume hologram under ultrashort-pulsed light illumination was derived. Then total diffraction intensity and diffraction efficiency were deduced. Study showsd that the diffraction intensity spectrum,total diffraction intensity and diffraction efficiency were in close connection with grating spacing Λ,grating thickness d,and readout pulse width Δτ. Through modulating these parameters,different extent of filtering for the incident ultrashort pulse can be realized. The results can be utilized to study the shaping of ultrashort pulse.