In laser diode-pumped solid-state lasers, the thermal induced distortion in laser crystal limits the scalability of high power output with high beam quality. Partially end-pumped slab laser with a stable-unstable hybrid resonator is an effective way to solve this problem. 110 W output with nearly diffractive-limit is obtained using Nd∶YVO4 as the gain media and a cavity less than 100 mm. The beam propagation factor M2 are 1.3 and 1.5 in the unstable and stable directions respectively at this power level. Spatial filting to cut the side lobes casued by hard-edge difrraction of output resonator mirror is also demonstrated. The typical propagation factors M2 are 1.09 and 1.2 after a spatial filter at 50 W operation.

A novel colliding-enhanced cavity is reported. It has low threshold and energy output of 100 mJ. Self Q-switched pulse duration is 20 ns, with 1.3 mrad of the angle of divergence. In some extent, the higher the pump voltageis, the narrower the output pulse widths; The longer the length of phase conjugate resonator, the wider the pulse widths; The shorter the focal length of the lens, the narrower the pulse widths; the longer the cell and focal length, the higher the output energy and the smaller the angle of divergence. The results of pulse widths and output energies and the angle of divergence in different conditions are given.

The optical properties of the angle tuning, resonation thresholds, and conversion efficiency curves are simulated for CLBO and BBO crystal by using the Sellmeier equation and the energy conservation in type-Ⅰ and Ⅱ. The wavelength tuning ranges of 237～289 nm and 807～2793 nm, 404～2800 nm in type-Ⅰ and type-Ⅱ are obtained for CLBO-OPO by 213 nm pumped, respectively. The efficiency is obtained that the efficiency of CLBO is larger than that of BBO in type Ⅰ, and the efficiency of CLBO crystal is less than that of BBO in type Ⅱ, but the maximum efficiency is obtained in the ultraviolet waveband for CLBO than that of BBO crystal. It is proved theoretically that CLBO is a excellent ultraviolet crystal.

A novel method to measure the laser induced damage threshold (LIDT) of crystals is presented. The method involves confirming the cross-sectional power density distribution of incident laser and measuring crystals' radii of damage spots, then calculating the corresponding LIDT. For Gaussian laser beam, a relational expression between crystals' damage threshold and radius of damage spots has been reasoned out. Different from other measuring method, this new method can qualitatively and exactly measure crystals' laser induced damage threshold. Using the method, the laser induced damage thresholds of LiNbO3 single crystals doped with different MgO concentration are measured under the same laser condition. The measuring results agree well with both former relevant reports and authors′ theoretical analysis. The applicability of the new method is discussed. It is shown that the proposed method is fast, accurate and can be widely used to precisely test crystals' laser induced damage threshold.

The theoretical study shows that the two frequency components of a polychromatic light can interact each other in photorefractive polymers, and the bright-bright, dark-dark and bright-dark polychromatic spatial soliton solutions for optical wave evolution equations are presented under some steady-state conditions. A bright soliton can be formed in the photorefractive polymers with positive refractive index perturbation supported by a proper dark soliton, and a dark soliton can be formed in the photorefractive polymers with negative refractive index perturbation supported by a proper bright soliton.

As the transmission bit rate increases to 10 Gb/s, especially 40 Gb/s and beyond, polarization effects in optical fibers have become one of the significant limiting factors for long-haul transmission. The polarization characteristics of fiber are mainly polarization mode dispersion (PMD) and polarization dependent loss (PDL). While the pulse root mean square (RMS) broadening is a main physical variable to judge signal transmission performance. The interaction between PMD and PDL and their combined effects on pulse broadening are investigated in detail. The relation between PMD vector and PDL vector in fiber links is described analytically. In presence of PMD and PDL, analytical expression of pulse broadening in optical fibers is derived, and chromatic dispersion, chirping are also considered simultaneously. The model can be used to analyze higher order PMD, PDL and pulse broadening in any linear fiber communication system.

Based on the standard coupled equations describing bi-directionally pumped fiber Raman amplifiers (BDP-FRAs), a generalized automatic algorithm with the help of genetic algorithm and cascaded global convergent Broyden method is proposed for the design of broadband BDP-FRAs. The main advantages of this algorithm are higher efficiency, easier convergence and wider application. The numerical calculation illustrates that the gain flatness for 10 THz gain bandwidth is well within ±0.6 dB for three kinds of FRAs

Based on the transformation theory of ray matrix and the overlap area integration method, a theoretical analysis has been performed and the coupling efficiencies of optical signal have been calculated in single-mode fiber, expanded fiber, laser diode, and optical waveguide etc, in taking into consideration of specific boundary condition in each case. The obtained formulation is applicable in many practical issues. A manufacture method of expanded fiber is presented and described with our newly formed theory. A comparison of theoretical with experimental results was made.

A non-synchronously-numerating experimental system is applied to measure the gain of two-wave coupling in a Ce∶KNSBN crystal while the signal beam and the pump beam are non-simultaneously opened, and the effect of fanning on the dynamical characteristics of two-wave coupling is discussed. It is shown that there is significant writing beam intensity threshold effect of fanning as 632.8 nm He-Ne laser is used to write the volume grating in Ce∶KNSBN crystal, and obvious fanning occurs only if the writing beam intensity is higher than 30 mW/cm2. Modified wave-coupling equations are used to simulate both the dynamical process of two-wave coupling and the gain as a function of the opening time interval between the signal beam and the pump beam. The theoretically calculated results are coincident with the experiment data.

The magnetostatically coupled multilayer films (GdFeCo/AlN/TbFeCo) were prepared by sputtering method. The measuring results by vibrating sample magnetometer and Kerr rotation hysteresis loop measurement indicate that the Kerr rotation angle of the readout layer (GdFeCo) at no external field is almost zero, and the magnetization direction of the readout layer is in-plane at 25 ℃; the Kerr rotation angle of the readout layer has a maximal value (0.54) at 125 ℃, the magnetization direction of the readout layer is perpendicular at 125 ℃; the magnetization orientation of the readout changes from in-plane to perpendicular with the raise of the temperature. The magnetization direction of the readout layer changes rapidly from 75 ℃ to 125 ℃. The magnetization mechanism of the films was studied. It was found that the magnetization reorientation of the GdFeCo layer is effected by the saturation magnetization and the effective anisotropy energy, but the transition occurs mainly as a result of the changes in the saturation magnetization. The saturation magnetization and the demagnetizing energy of the GdFeCo layer decrease with increasing temperature, and the transition of the GdFeCo layer from in-plane to perpendicular magnetization occurs. The films are suitable to be used as center aperture detection-magnetically superresolution (CAD-MSR) recording media.

Standing wave total internal reflection imaging technique can obtain high resolution images of a sample along both axial and lateral directions. The variations of the interference patterns with incident condition of excitation light as well as refractive index of medium, and the differences between standing evanescent wave and standing propagating wave are theoretically investigated. The analysis shows that when contrast of the evanescent interference pattern is 1, optimal point spread function (PSF) can be obtained. Due to the narrowed FWHM of PSF, the lateral resolution increases with the decrease of period of the evanescent interference patterns. However, the intensity of PSF side bands increases, which will lower imaging quality.

Some integrated optics devices can be made based on the interdigital electrooptic bragg diffraction grating. The point-matching method is extended to the analysis of interdigital electrooptic bragg diffraction gratings. This method gives a simple and fast analytic expression of the electric fields in the structure. The field distributions are used to calculate the optical and electrical characteristic parameters of the gratings. The effects of finite conductor thickness have been taken into account in the analysis. It is shown that the simulation results agree well with the measured data.

Devices with a structure of ITO(indium tin oxide)/TPD(N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine)/Alq3[tris-(8-hydroxy-quinolinato) aluminum)/Liq(8-hydroxy-quinolinato lithium)/Al, here Liq was used as an electron injection layer,were investigated. Effect of Liq thickness on the electroluminescent efficiency and characteristics of current density-voltage was investigated. Experimental results show that a device with 0.5 nm thick Liq as an electron injection layer was the highest in the efficiency which was about five times higher than that without Liq. This may be attributed to the enhancement of electron injection from the introduction of Liq, which generate a dipole layer and form an ohmic contact between aluminum electrode and Alq3 organic layer. Increase the thickness of Liq layer leads to the decrease of device efficiency and the increase of operating voltage. Comparing with same structure devices using LiF as an injection layer, the trend of change of device performance with the thickness increase of injection layer was similar, however the devices using Liq as an injection layer are less sensitive to the thickness of injection layer. This is because that LiF is an insulator and Liq is a semiconductor. This is very important for use of a large size substrate in the mass production.

Because two shearing object beams travel in the same direction when Wollaston prism is used as image-shearing device in traditional speckle shearing interferometry. It is difficult to realize phase-shifting technique by separating the two beams for introducing some additional phase changes between the two beams. Rotating stage phase-shifting method (RSPSM) presented in this paper could introduce additional phase changes by rotating the test object a small angle, which is fixed on a rotating stage. Theoretical analysis shows that RSPSM can introduce a stable and linear additional phase changes. The relationship between rotating angle and additional phase is offered. A typical experiment about RSPSM is carried out by using a centrally loaded clamped circular plate. The experimental results are offered. It shows that rotating stage phase-shifting technique could effectively obtain displacement derivative field from fringe patterns of test object.

Using matrix equation, the population distribution and absorption characteristics in the molecular Y-type energy level system with two driving fields are calculated and analyzed. The generation of double dark resonance and double electromagnatically induced transparency in this energy level system is obtained, its physical mechanism is discussed. The effect of the quantum interference of the spontaneous emission on the electromagnetically induced transparency are also discussed. Coherence cancellation of the spontaneous emission can form the ultra-narrow line width and enhance the absorption, whereas the coherence enhancement of the spontaneous emission can form the wide absorption line width and weaken its intensity, above calculated results are analyzed with the dressed state theory and agree with those by the density matrix equation.

Entangled states play an important role in quantum computation and quantum information. A partially entangled state is applied to be a resource and it is proposed a scheme where one can successfully realize copying and orthogonal complementing of an unknown EPR (Einstein-Podolsky-Rosen) pair in a certain probability so that two parties of communication can obtain the EPR state. The first stage of this scheme is to apply a quantum channel, that is a partially entangled channel of three-particle, to teleport an unknown EPR state. Based on the no-cloning theorem, the input state will be destructed at the place of sender in teleportation. In the second stage, through introducing an auxiliary qubit, Alice(a sender) can achieve a copy or an orthogonal-complement copy of the EPR pair with assistance of Victor(a state preparer) in a unite probability. Reestablishment of quantum state is realized in the scheme.

The X-ray compound lens is a novel optical device that focuses X-ray radiation by refraction effect. The theoretical and numerical study of such a device is reported, including the derivations of the diffractive screen function of the compound lens and the equations of the intensity distribution in the focus plane by considering both refraction and absorption effect and diffraction theory. The first-order and the second-order origin moments are used to describe the optical performances of the device at the image plane. This theoretical method can be easily generalized to the case of the compound X-ray lens with a double-concave shape. The structural parameters of an X-ray compound lens with Al material are designed. The second-order central moment of the intensity distribution at the image plane and dependence of the radiation intensity at the focus on the structural parameters of the compound lens are analyzed by using numerical calculationm at the focal plane after X-ray radiation passes the compound lens is calculated as X-ray raidation energy is 0.93 keV, 9.89 keV and 29.78 keV, respectively.

Based on analysis of the coupling theory, the two auto-aligning methods and programs are designed. Experiment results using single mode fiber as standard waveguide show that the average end-coupling loss is 0.075 dB, the standard deviation is 0.0099 dB at the wavelength 1310 nm, and is 0.0062 dB and 0.0066 dB at 1550 nm, respectively. A process only needs 2 min. When it comes to fiber-SiO2 waveguide-fiber system, the average end-coupling losses are 0.140 dB and 0.109 dB, and the standard deviations are 0.0082 dB and 0.0107 dB, at 1310 nm and 1550 nm, respectively. The whole process is accomplished within 8 min.

The probability distribution of the differential group delay for different mode coupling is simulated with Monte-Carlo method. By fitting the results of the simulation, probability distribution function for different mode coupling is obtained. It is found that the probability distribution function of the magnitude of the dispersion changes from a very sharp δ-like function to Maxwellian with increase of coupling times of the two polarization modes. At certain coupling times, the probability distribution function is Gaussian. By taking two direction cosines of the polarization mode dispersion (PMD) vector for statistics, it is found that with increasing of the coupling times, the probability distribution of the direction cosines of the PMD vector changes from a Gassian and a δ-like distribution to a uniform distribution.

The influence of perturbation on the propagation properties of optical bright-soliton-like pulses is investigated in optical fibers by means of variational method, and the evolution equations for the parameters of the optical bright-soliton-like pulse is derived. These equations are the unity of the evolution equations for the parameters of the optical bright-soliton-like pulse among monomode optical fibers, the fiber with slowly decreasing dispersion or dispersion-managed optical fibers. By these equations, the perturbation of linear high-order dispersion in the fiber is calculated. The results show that linear high-order dispersion affects the position and the phase, doesn't affects the amplitude ,the width and the chirp of the bright-soliton-like pulse. The slowly decreasing dispersion affects all of the parameters of the optical bright-soliton-like pulse.

Crossing waveguide is an important unit in integrated optics. The generalized Douglas (GD) scheme for variable coefficients is applied to wide-angle multistep finite-difference beam propagation method (FD-BPM). Aiming at the structure and refractive-index profile of wide-angle cross waveguide, the optical field distribution has been calculated by the method. Compared with Crank-Nicholson (CN)scheme in the same computational time and resource, the method has two characteristics

Digital projection display has become the mainstream in modern display field. Accurate focusing of the array pixel devices in these systems determines the quality of the displaying effect. Auto-focusing of the pixel devices is the key technique to rise the productivity. Based on the images captured by CCD (Charge Coupled Device) in array pixel device projector, several sharpness evaluation functions, such as gradient operator, Laplacian operator, Sobel operator, Prewitt operator, variance method, and entropy method, are analyzed. Using these evaluation functions, automatic focusing is realized. The characteristics and the auto-focusing result is compared with each other. The experiments indicate that good stability and insensitivity to noise and good regulation effect can be obtainted by variance method.

By use of holographic theory,Fourier transform frequency spectrum analysis and sampling theorem, this analysis of some fundamental issues about digital hologram by computer simulation and the experiment of digital grating is given. The results show

Based on the theory of six-temperature model rate equation a theoretical model on calculating the kinetic characteristics of a grating-tuned TEA CO2 laser is given. As an illustration, the output characteristics of a grating-tuned TEA CO2 laser is calculated out by this theory. In the calculation, a grating with a brazing angle 30° and 120 grooves per millimeter is used. The laser is assumed to be of an active volume 0.9 litter and total gas pressure 61.3 kPa under temperature 300 K. By numerical calculation, the following results are obtained

Basing on experiments and theories, we study frequency doubling in a KTP crystal on Nd∶YAG laser by the resonant external ring cavity. The Nd∶YAG laser average power is 50 W with Q-switch and its frequency is 1005 Hz. In the experiment we obtain 0.532 μm green light output with 31.4% light conversion efficiency when 1.064 μm input average power is 35 W. With the experimental results, we analyze the experimental results for the characteristics of ring cavity frequency doubling and summarize its strength and weakness. We compare fundamental frequency laser and second harmonic generation in terms of laser light quality. The thesis provides some pictures of beam focuses acquired with CCD, compares some experimental results with those pictures. We put forward a theory of the ring cavity frequency doubling in this paper.

A folded 3-mirror laser resonator in which a Cr4+∶YAG crystal is employed as a saturable absorber for passively Q-switching and a Brewster plate to compensate astigmatism was designed. The resonator has small radius of laser waists, so it is very suitable to the laser diode pumped intercavity frequency-doubling lasers with quasi-phase-matched frequency-doubler. The expressions to calculate the radius and the place of laser waist, curvature of the mirrors used in the resonator, the thickness of a Brewster plate, and folding angle of the resonator were presented. The performance of continous-wave laser diode pumped passively Q-switched PPLN intercavity frequency-doubling laser with the folded 3-mirror laser resonator was investigated. As the result that both fundamental and second harmonic waves have the same polarization, no green-noise problem exists. The pulse series of laser output are stable. The laser has the average output power 42.7 mW under the CW input power 500 mW.

A design method of beam-converting annular resonator is presented. And the bare cavity modes of this resonator are calculated, the advantages of beam-converting annular resonator are analysed. The cavity′s stability is also studied with home-made three-dimensional ray tracking program. It showed that beam-converting aannular resonator is a valuable resonator with high extraction effiecency and near-diffractive-limit optical quality, and can sustain certain disturbance. The methods presented are also valuable to the design and calculation of other complex laser resonators.

Physical method, including thermal evaporation and magnetic sputtering, and chemical coating method are applied to prepare organic-inorganic composite chromotropic film. The chromotropic film showing obvious opto-chromo effect with the change of incidence angle and view angle, can be used as a counterfeiting preventing material. The structure of the film system is designed as PET/Cr/dielectric/Al according to the optical interference principle of multiplayer. The dielectric materials are polymer and SiO2 respectively. The SiO2 prepared by sol-gel method shows nano-holes. Its refractive index is between 1.15 and 1.45 by varying the method and condition of catalyst and gel process. Fabrication method and film characteristics are described.

The residual stress in ZrO2 films prepared by electron beam evaporation was measured by viewing the substrate deflection using an optical interference method. The influence of deposition temperatures and deposition rates on the residual stress was studied. The results show that residual stress in ZrO2 films changes from tensile to compressive with the increase of deposition temperature and deposition rate and the value of the compressive stress increase with the increase of deposition temperature. At the same time, the microstructure of the ZrO2 films was inspected by X-ray diffraction (XRD). The relationship between the residual stress and the microstructure was also discussed.

Based on the Kirchhoff law, a practical dual-wavelength high-precision fiber-optic colorimeter using LiTaO3 pyroelectric detector is presented. According to the relationships between various technical parameters and main specifications (temperature resolving power of single detector, linearity of R(T)～T curves, temperature measurement sensitivity and relative temperature sensitivity), a method of optimal parameter selection for determining two operating wavelengths of a new kind of the practical IR fiber-optic colorimeter using LiTaO3 pyroelectric detector is presented. Experimental results show that temperature measurement sensitivity exceeds 1.0×10-4 ℃-1, and relative tomperature sensitivity and temperature measurement accuracy are better than 0.8 and 0.15% respectively at 400～1300 ℃ and λ1=2.1 μm, λ2=2.3 μm which reach design requirements.