In adaptive optics system, wavefront computation refers to a class of processing consisting of wavefront slope computation, wavefront reconstruction and wavefront control algorithm. We studied the realization of the optimization mapping of the wavefront computing algorithm from the representive layer to the architecture layer. Two SIMD-based parallel algorithms, the doubling algorithm and the partitioning algorithm are proposed according to the existing parallel computing theory. On the basis above, the MAC cycle and I/O cycle are used to scale the performance of the two algorithms. Their computing efficiencies on the SIMD array processor are analyzed and compared in detail.

A probability distribution model for the light log-intensity fluctuation in turbulent atmosphere was introduced by taking consideration of the skewness and the kurtosis. The model is suitable for fitting the probability distrbution from experimental data. It was found experimentally that under the weak fluctuation condition the probability distribution is close to a normal distrbution when the turbulence is well deveploped, otherwise the ditribution will deviate from the normal distribution and the skewness of the log-intensity probability distribution is alwsys negative and the kurtosis positive.

A new numerical method-transfer function method-for analysis and calculation of optical waveguides is presented. By using this method, the characteristics of propagation for diffused planar waveguides are calculated and compared with the finite element method. The results show that it is a relatively simple and exact method for using transfer function method to deal with the optical waveguides with graded refractive index profile.

Formulas and method of calculation are presented for analysis of optical nonlinearity and bistability of TE modes in a multiple quantum well waveguide with nonlinear cladding. It is demonstrated that in the thin film approximation, the method of root-mean-square equivalent index for the waveguide core is an accurate, efficient and time saving method for characteristics analysis. Dependence of modal refractive index on total waveguide power, bistability between core power and total power, dependence of field profile on modal index are analysed and the influence of waveguide parameters on them are discussed.

A theoretical treatment on the propagation characteristics of magnetostatic forward volume wave (MSFVW), in a four-layer YIG-GGG (Yttrium iron garnet-Gadolinium gallium garnet) waveguide structure under a nonuniform bias magnetic field, and related guided-wave magnetooptic (MO) Bragg diffraction is presented. A nonuniform bias magnetic field of appropriate profile along the propagation path is found to have the effects of enhancing the power density of MSFVW and thus the corresponding MO Bragg diffraction efficiency, and to have the possibility of controlling the degree of divergence in the diffracted light.

A novel direct volume reconstruction method based on reverse geometry for cone beam X-ray projections is presented. We combine the cone beam boundary reconstruction with reverse geometry by extending one or two detectors to many point-shaped detectors located purposively in 3D space. The boundary reconstruction algorithm and its numerical simulation on two volume phantoms have shown that the new reverse geometry is worth considering and exploiting compared to the conventional X-ray cone beam boundary reconstruction in case of X-ray projection noise.

The problems are analysed in practical 3D detection by phase approaching of projected grating that frequency-moving in frequency domain and the correspondence between measured surface and reference plane have great effect on the accuracy of phase-demodulating. An appropriate method for avoiding frequency-moving and a new concept of full-field reference plane are proposed. Their perfect perfomance has been verified.

A series of image processing methods of fringe analysis is given. It includes mean processing of intensity distribution using the anti-Gauss distribution, edge detection instead of binary method and an effective thinning method. The practical methods have been used to process the interferogram of optical computer tomography and good results are obtained.

A diode-end-pumped Nd:YLF laser with self-starting additive pulse mode-locking is investigated, The mechanics of the pulse shortening and the condition of the self-starting are analized. When pumped with the maximum power of 2.4 W, stable CW mode locked trains of 2 ps pulses are generated at 1.053 μm, with an average effective output power of 76 mW, corresponding to a peak power of 283 W.

Based the time-and space-resolved spectroscopy and the measurements of intensity of resonant double-lines 396.15 nm and 394.40 nm from laser induced plasma, the time- and space-evolution characteristics of resonance double lines of aluminium in a plasma were obtained and mechanism was discussed. Air was used as surrounding atmospheres. The pressure was set up to 101 kPa.

Narrow line fluorescence spectra of Eu3+:Y2SiO5 crystal are obtained by exciting with Ar+ laser at 514.5 nm, 488 nm and He-Cd laser at 441.6 nm. Complex spectral structure is analyzed and identified, which is understood as originating from taking off the energy level degeneracy of Eu3+ in the host crystal field and the possession of two inequivalent lattice sites of Eu3+ in the host crystal. X-ray powder diffraction pattern of Eu3+:Y2SiO5 shows that the the crystal is monoclinic. The lattice constants a, b, c and β are obtained by a simulation with the measured difraction angles, and found that the lattice constants a, b, c are slightly larger but very close to those of undoped Y2SiO5 crystal.

Spectral performances of Yb:YAG crystal were studied. The optimal Yb3+ doping level in Yb:YAG crystal is 10at%, which is determined by the fluorescence lifetime measurement. It is shown that the cooperative up-conversion processes of Yb3+→Tm3+ energy transfer is responsible for the fluorescence quenching at high Yb3+ doping level. 300 mW of pulsed laser output power at 1030 nm was obtained by means of InGaAs LD pumped 20at% Yb:YAG crystal thin chip.

High quality optical crystal of Cr, Ca:YAG was grown by Czochralski method and annealed in an oxidization atmosphere successfully in our laboratory. VIS-NIR absorption spectra, crystal-field parameters and characteristics of Cr4+ centres in the crystal, which are influenced by divalent compensation Ca2+ ion, are determined and analyzed in detail. Some evidences suggest that a reasonable doping concentration would be favourable to emitting tunable laser from such a laser crystal.

A theoretical explanation of induced self-pumping phase conjugation (ISPPC) is presented. The bistability and reversibility and irreversibility of ISPPC in given conditions are obtained by numerical calculation of the corresponding coupled-wave equation. The calculated results show qualitative agreement with the experimental results obtained previously.

Based on the birefringence effect, a practical reflective fiber-optic temperature sensor was developed with the polarization-modulated method. The relations among the accuracy, sensitivity and parameters including the source, crystal and optical fiber, are analyzed in terms of theory and experiments. The methods of selecting the optimal system parameters are illustrated.

By using the high frequency saturation filtering effect and dynamic carrier recovery time, the dependence of the frequency chirping and intersymbol interference (ISI) of a wavelength converter based on cross-phase modulation in Mach-Zehnder wavelength converter is analyzed. While the extinction ratio is kept the same at different probe power for out-phase converting, the poorer performance of the converted signal is due to a longer gain recovery time and the larger intersymbol interference. But for in-phase converting, the high probe or fast carrier recovery time is not surely better than that of low probe power.

In the distributed optical fiber Raman photons temperature senser (DOFRPTS) system, spontaneous Raman photons are carriers of temperature signal. On the 2 km optical fiber, 1000 points have been sampled on time used for the measurement of temperature field in space. The position of measurement point was determined by Raman scattering optical time domain reflection (OTDR) technique. Signal and noise of the system have been discussed, the measured temperature accuracy of the DOFRPS system is ±1℃ determined by S/N ratio.

A rigorous vector grating analysis approach-BKK approach, which can be used to analyze the big caliber and big view binary optical system, is introduced. This method is applied to calculate the diffraction efficiencies accurately for arbitrary grating profiles, incident angles, substrate indexes and wavelengths in the same order of grating period. The diffraction efficiencies are given and compared with scalar results.

Based on the diffraction optical principle, a formula of the diffraction efficiency and etching depth error of the microlens is obtained. The results show that the time control method of ion beam etching meets the needs of micro-fabrication of L=1′s microlens and the etching depth error should be smaller than 87 nm in the micro-fabrication of L>1′s microlens.

A new plane grating monochromator is used in the surface-physics beamline at the Hefei National Synchrotron Radiation Lab. (NSRL) as its light-dispersing instrument. Its optical imaging system consists of a plane grating and a spherical mirror. The wavelength tuning is performed by rotating the pre-spherical mirror around an axis outside of the surface while rotating the grating around its center. The monochromator offers high optical transmission and high spectral resolving power at 4～120 nm wavelength range.

By utilizing the properties of liquid crystal molecular alignment controllable by electric field as well as its optical anisotropy, a new type Fresnel phase waveband plate has been designed. This device has the advantages of easy fabrification, low cost and resistance to scratch.

The expressions for correlation functions, power spectrum and correlation time of the intensity of a single-mode laser driven by two white noises with a exponential function correlation form were calculated by linear approximation method. According to the calculated results, the effects of correlation strength and correlation time between noises on the above quantities are discussed, and are compared with the situation of a delta function correlation form between moises.

A new scheme is proposed to realize the Fredkin quantum logic gate by using laser-controlled excitation of state in the three-mode laser and three-level system, in which the population depends on the laser phases and amplitudes.

By using KTP crystal as intracavity frequency doubling generator of a mode-locked Nd:YAP laser, efficient SHG in colliding pulse mode-locked (CPM) unstable resonator with antiresonant ring (ARR) and confocal unstable resonator has been demonstrated. The energy conversion efficiencies are 53.4% and 60.2%, pulse durations in fundamental wave are 8 ps and 18 ps, and the maximum energy fluctuation in second harmonic wave are 10.6% and 12.5%, respectively. The characteristics in both resonators and their experimental results are theoretically analyzed.

Hyperfine Zeeman spectra of the cesium atoms 62S1/2→52D5/2 electric quadrupole transition is studied experimentally by the thermionic diode and photoionization technique, corresponding calculations for the energy structure and relative intensity of the transition are conducted. The experimental and theoretical results are compared and discussed. The results of this study are significant to the efficient use of a high-resolution external field spectral method.