Sampled fiber bragg grating (SFBG) is numerically analyzed by using the transfer matrix methods. Some new tapped schemes to improve the characteristic of reflection (transmission) spectrum are proposed. And the sampled grating with a reflection peak separation of 0.8 nm and 1.6 nm is demonstrated.

Dependence of coupling coefficienct on guided wave power of a nonlinear directional waveguide coupler formed by two optical planar waveguides placed in close proximity is discussed. Formulas and procedure of the calculation is presented for the interaction region being covered with nonlinear Kerr-type dielectric material. Numerical examples and discussions are given for both self-focussing and self-defocussing material.

Soft X-ray holograms within water-windows are recorded in photoresist and reconstructed by using numerical technology. The 3.20 nm soft X-ray used in the experiments are a bending magnet radiation from a 800 MeV electron storage ring and have been monochromatized by a linear monochromator. The estimated resolution of the reconstructed images is better than 2 μm and remains to be improved in the future.

The principle of speckle holography was intruduced briefly. The observation of high resolution image reconstruction with speckle holography for two astronomical double stars ADS11344 and ADS16648 was reported.

The concepts of uncertain pixel and pattern are used to improve the distortion-invariant ability of morphological hit-or-miss transformation (HMT). A method called joint rank-order multi-value hit-or-miss transformation (JRMVHMT) is introduced, which reduces the decision effect of the pixels that is easily disturbed by rotation and scaling distortion. Because of not losing information of the input images, JRMVHMT can realize the precision recognition between two images and has a better distortion-invariant ability for scaling and rotation than the ordinary HMT. The comparison of JRMVHMT with the ordinary HMT in theoretic analysis and experiments is given. Based on an incoherent correlator and multil-value complementary encoding, JRMVHMT is realized for binary image recognition and gets satisfying results.

Though the image quality degradation caused by atmosphere turbulent noise can be overcomed and the diffraction-limited resolution image reconstruction of the telescope can be achieved with the method of speckle masking, there are many kinds of noise in varying degrees in a real speckle detector, which introduce bais terms into the average power spectrum and bispectrum of speckle iamges and distort gravely the recovery of module and phase. The noise problem in image reconstruction observation with the method of speckle masking was discussed and a positive restriction method used to correct the noise bais terms in bispectrum, then a high resolution image reconstruction observation of objects: binary ADS16800 and triple star Hld171 (ADS16648) was reported.

An adaptive optimum path method and least mean square (LMS) phase unwrapping as a typical path-independent method are discussed. In the latter case Poisson equation and its discrete formulation are derived. The multigrid algorithm for solving this equation is given in detail. Especially a weighted multigrid algorithm aimed at cases with boundary and blockage is presented. Then a modified multigrid algorithm which combines the advantages of two classes of phase unwrapping algorithms is developed. It takes the results of the adaptive optimum path method as initial guess of the iteration of multigrid and a high accuracy is reached within a considerably faster convergence speed. In the simulation experiment an interferogram of a flow field containing opaque objects and the related results are given. The method is applied to a real interferogram and is proved that it is effective and practical for reconstructing wave-front containing opaque object.

Statistical characteristics of double scattering speckle field in longitudinal motion is studied in detail. Its autocorrelation function of amplitude and intensity fluctuations are derived. At the receiving plane within the far-field diffraction region, the autocorrelation function of speckle intensity fluctuations is not generally statistically stationary. While, the time-varying speckle intensity variations become statistically stationary in the vicinity of the center of far-field diffraction plane. The velocity of the diffuser is in inverse proportion to the correlation time. The theoretical result is consistent with the experimental result.

A new synthesized push-pull azobenzene compound was doped in PMMA film, its multiple storage characterization was studied, and the photograph recording of triple storage as well as observation of photoelectric storage time situation were performed; the competition recording among multiple storage was studied. The mechanism of relation phenomena of multiple storage is explained.

Near-field recording optical disc is a new optical disc recording technique. It has two characteristics: 1) extreme high recording density; 2) very high seeking speed. Characteristic of near-field optical disc recording technique is discussed. The write energy problem of a read-writing system with dynamic state in near-field optical disc recording technique is presented; Simulation calculations for the energy transmission between the flying head and optical disc are carried out.

A new kind of diffractive 2-dimension laser scanner is proposed, designed and fabricated using laser direct writing (LDW) and reactive ion etched (RIE). The scanner is tested and the parameters of the 25×25 degrees scanning range and 41% diffractive efficiency are obtained.

The noise structure measurement of fs amplified laser pulses by means of a 107 high dynamic range triple correlator is reported. Results show that there exist noise pulses with the amplitude of 10-5 of the main pulse before and after it.

A new coherent reception space communication adopting photorefractive quantum device is discussed. The complicated intermediate frequency tracking electronics can be omitted in this system, as compared with traditional heterodyne reception. It is also capable of suppressing the interference such as wavefront distortion, random vibration of polarization and Doppler frequency shift, which are common to optical transmission in turbulent atmosphere between mobile vehicles. The experimental result of homodyne reception and the wavelength conversion characteristics of photorefractive quantum device are reported.

Optical-field ionized plasma parameters are studied to find the optimum laser intensity for production of KrIX plasma suitable for the generation of collisionally excited XUV laser at 31.9 nm.

The effects of laser beam fluctuation on the temperature of material were studied for laser beam used as a thermal source. The noise source was firstly introduced into the differential equation of laser thermal conduction and the equation was solved. The temperature distribution was influenced by the noise. The fluctuation is strong at the surface of the material and weak in the deep of the material. The temperature distribution is related with laser thermal interaction process. With increasement of the laser heating time, the fluctuation increased. Moreover, The temperature distribution is also affected by the thermal conductivity K, thermal diffusivity k and absorptivity ε. Some suggestions are proposed for decreasing the influences of laser beam fluctuation.

Using xenon flash lamp as pump source and Cr4+:YAG as passive Q-switch, we have performed the Q-switched laser operation at 1.059 μm with a Nd:Sr5(PO4)3F crystal and measured the single pulse output energy, pulse width and repetition rate under different small-signal transmission of Cr4+:YAG and, different reflectivity of output reflector. Meanwhile, the Cr4+:YAG Q-switched coupling rate equations for Nd:Sr5(PO4)3F crystal were given. The numerical solutions of the equations were in agreement with the experimental results.

The equalizing property of twin-core erbium-doped fiber amplifier has baan studied by establishing a theoretical model and numerically simulating the charaxteristics of the amplifier. The twin-core erbium-doped fiber amplifier can provide different gains for different channels and self-heal the extra channel loss between amplifying stages, thus equalizes the output signal level. The twin-core fiber amplifiers is very suitable for the multi-wavelength, multi-channal fiber networks.

The wide band wavelength tuning external-cavity semiconductor laser was theoretically and experimentally analyzed. The maximum tuning range and the continuous tuning condition were given. The programmable wide band tuning external-cavity semiconductor laser has been investigated. Its principle, configuration and control technical were introduced briefly. As wide as 75 nm tuning range and 0.01 nm tuning resolution were realized.

Diamond-like carbon (DLC) films have been deposited by ultrashort pulsed excimer laser (KrF 248 nm, 500 fs, 10 mJ). The film depth is 0.5 μm, the growth rate is 0.3～0.4 μm/h, the microhardness is 55 GPa, the optical tansimittance is better than 93%(580 nm～3 μm)。 With the temporal and spatial emission spectra, the property of plasma plume generated by the ultrashort pulsed laser and its variation with the laser parameters have been investigated. The velocity of plasma plume is very high (1×107 cm/s), the duration is very short (200～300 ns), so the plasma flux is intensive and this is suitable to deposit DLC and other metestable material. We have used the ion probe to measure the plasma ion flux, the result is consistent with that of the emission spectra. Under different laser parameter, DLC films were deposited and the effect of laser parameter and plasma flux on the deposited film have been compared. The characteristic of the interaction of ultrashort pulse with the target and the formation of DLC by laser plasma have been discussed.

Based on the theoretical process model for positive photoresist, ray-tracing algorithm is used to calculate the time evolution of surface profiles produced by a locally dependent surface etching phenomenon. Depending on the simulation programs established, the final developed surface profile can be computed from any given distribution of exposure energy and development time. This provides a convenient way for investigating laser direct writing process. By introducing a threshold approximation in development process, the relationship between the initial distribution of exposure energy on the upper surface of the resist film and the surface profile after development is deduced, which provides an effective theoretical approach for laser direct writing technology.

By measuring the absorption and fluorescence spectra and the fluorescence lifetime of 3F4 state of Tm3+ ions in Tm:YAG crystal at different temperature, the effects of temperature on the spectra and the lifetime of 3F4 state of Tm:YAG crystal have been investigated. When the temperature increased up to 400 K, temperature induced fluorescence quenching has been observed.

Dye-doped and SiO2-based solid laser material in blue band was synthesized by sol-gel technique. With 308 nm XeCl laser as pump source, the laser output at 364 nm wavelength was obtained from the material under transverse pumping. In the case of 10 mJ pump energy, the derived blue laser energy can be up to 0.20 mJ.

Triangular lattice photonic crystal behaving in the electromagnetic zones constructed from fused silicon cylinders in styrofoam is fabricated. The transmission spectra of the photonic crystal with and without defects were measured. On this basis, the defect modes of photonic crystal were studied, and the potential applications of the photonic crystal were discussed.

Employing optical sources with different wavelength as the input optical signals of WDM system, the phenomenon of four-wave mixing in the experiment is analyzed. The amplitudes of four-wave mixing in different optical fiber chains are compared. In order to decrease the four wave mixing effect, the fiber with zero dispersion wave close to the signal optical pulse should be put far away Er-doped fiber amplifier in each amplifier spacing. The experimental phenomena are theoretically analyzed.

Two kinks of the slowing down in the optical tristability systems are studied. One is the critical slowing down at the edges of tristable region and the bifurcation, and their critical exponent is calculated; the other is the slowing down far from the critical point, which is concerned with the unstable steady points. The results show universal properties.

The dielectric thin films deposited on compound semiconductors devices by electron cyclotron resonance (ECR) plasma chemical vapor deposition (CVD) are characterized. The method to deposite antireflectivity coatings on 1310 nm semiconductor lasers with reflectivity less than 10-4 and its advantage are discussed.