The model for a new kind of underwater laser imaging system is proposed. The quantity relationships of imaging distance and quality of the system with the main system parameters such as the scattering angle of light beam, the visual angle and open time of gate of receiver are calculated. The results show that the imaging quality and distance can be increased by decreasing the influence of background-lights and increasing the quality of pulse-light. The theoretical value of imaging distance for the new kind of underwater laser imaging system in the ordinary seawater can reached 25 times of the attenuation lengths, which is as 4～5 times long as that for the synchronous scanning and range-gated systems.

The pressure and the cross-temperature properties of the fiber grating pressure sensor with a polymer jacket is studied. Because of the driving effect of the polymer substrate, the measured pressure sensitivity is increased by more than 31.7 times than that of a bare fiber grating.

The atmospheric back-scattering parameters at 532 nm wavelength in low layer were measured by using AIOFM′s L625 Lidar at Hefei in March and May of 1997. The measured data are analyzed in the paper.

The reason why the measuring results are probably wrong when measuring the topography of stair-like surfaces is analyzed, and the new data processing method is presented, which can be applied to correct the measuring results of stair-like surfaces’ topography. The method has been successfully used in the system for measuring the 3-D surface topography of diffractive optical elements.

The phase encryption and decryption of optical image in Fourier domain are studied by computer simulation. The chaotic sequence is used to construct the phase array to compress the data of decryption key to make it saving and transferring conveniently. A novel phase-ring distribution is used to make encrypted image with a rotative invariance so that the orientation of encrypted image is unconsidered during decryption. The noise can be reduced and the edges can be enhanced because this type of phase array has some functions as same as high-pass or low-pass filters. In this encryption method the ultra-low-frequency components of encrypted image in Fourier domain is more important and has a greater influence on the quality and signal-to-noise ratio of decrypted image than the high-frequency components do.

The multi-beam holographic optical head which combines the multi-beam optical head with holographic optical head is proposed. This optical head has a light and compact structure, and works with parallel mode. Consequently, it not only can improve data transfer rate of driver but also shorten the random access time. In this paper, the multi-beam holographic optical head is investigated theoretically and experimentally.

An anti-counterfeiting approach combining CGH and holographic interference is presented in this paper. It is flexible in design and possesses a high anti-counterfeiting ability. It can be reconstructed by common white light source and has a practical value in the future.

In this paper, an algorithm based on watersheds algorithm and fuzzy logical catchment basins incorporation is proposed and applied to articial object segmentation and natural background suppression and elimination.

This paper reported the bending strength improvement with relation to cobaltic phase structure of laser heat treatment in the surface of cemented carbide. The change of surface structure of YG20 cemented carbide was analyzed. The energy density with relation to bending strength are discussed. The microhardness, wear resistance, toughness of cemented carbide are improved. Some experimental results were given.

Left testes of male mice in two groups were irradiated by the He-Ne laser with two different powers. Synaptonemal complex (SC) of spermatocytes with a surface microspreading technique were examined by the electron microscopy. No significant increase in frequency of SC aberrations was observed in the irradiated left testes of the two experiment groups. After irradiating the types of SC aberrations, involving breakage, LE breakage, asynapsis, synapsis irregularity and ring, were not radically different in the experiment groups from the control. The laser energy density for the experiment was much higher than for clinical treatment. The results show irradiating testes by He-Ne laser isn′t able to induce SC aberrations.

By the method of laser microbeam puncture, the maturing embryoes of cotton were transformed with plant bivalent expression vector pBLGC including β-1,3-glucanase and chitinase genes. Fungal challenge of T1 generation with Verticillium albo-atrum were carried out by dipping their roots into hyphal and spores solution. The survived T1 seedings were subjected to Kan-resistant assay, and the results showed that 9 out of 29 T1 plants showed obvious Kanamycin resistance (Kan 1%). Upon PCR analysis, 7 out of 9 Kan-resistant plants produced a PCR fragment with expected size, indicating that they are probably transgenic. After T1 plants in disease-inducing plot were subjected to the period, in which the Veritcillium wilt serious took place, 7 PCR positive plants showed obvious resistance to this fungus, at last, flowered and bore cotton bolls normally, while the other T1 plants and the non-transformants all died of infection. This result primarily suggested that the foreign genes had integreted in cotton genome, and the transgenic plants showed high resistance to Verticillium wilt.

This paper presents experimental studies in which the drying corn (Zea may L.) seeds were irradiated by He-Ne laser at lower power. The measurement result showed that the soluble protein and nucleic acid contents in the corn seedling were enhanced after using laser irradiated drying seeds, while their SDS-PAGE spectra bands number and 3H-Leu labeled soluble protein radioactivity were increased. According to this, it could show that soluble protein synthesis of corn seedling could be promoted by He-Ne laser radiating drying seeds.

The ASE of erbium-doped fiber pumped by 980 nm laser diode is measured and the noise figure of EDFA pumped by two 980 nm laser diodes is studied. Experimental results are in harmony with theoretical results.

A simple tunable all fiber erbium-doped fiber ring laser with large tuning range has been reported. Polymer-packaged fiber grating with high temperature sensitivity has been used as a tuning device. By changing temperature of the fiber grating, the laser has been tuned over a 38 nm tuning range.

Active-passive mode-locking was observed in Nd∶YLF laser when one of the mirror was replaced with a nonlinear mirror which composed of CLBO crystal and a dichroic mirror. Pulse shortening as much as 8 times in comparison with purely active mode-locking was measured. The individual pulse duration as short as 15 ps was obtained.

This paper reports 1.31 μm waveband semiconductor optical amplifier (SOA) based on tensile strained quantum wells and compress strained quantum wells. For TM mode the gain is enhanced by tensile strained quantum wells, the SOA performs with low polarization sensitivity. Under the condition of 150 mA bias current, the SOA shows 24 dB small signal gain and 1 dB polarization sensitivity.

The nonlinear propagation properties of the strong Gauss-pulse with the frequency near the photonic band in fiber grating are studied by using the variational principle. The results show that the width and the amplitude of the pulse remain with the propagation distance (likes a soliton) under the first-order approximation, but a linear chirp which changes with the propagation distance is produced at the same time.

Unresolved transition array model and MCDF method are applied to calculate in detail the line and band spectrum for Ni-like ion of Au in the 0.3～0.6 nm range. The better agreement between theoretical calculation and experimental measurement compaired with the results of the calculation only using the UTA model indicates that it is resonable and necessary to correct the UTA model using MCDF method when the transition array contains very few number of lines.

The optically excited vibrating mechanism of the micro silicon beam is experimentally studied. It is shown that the energy transforms fr om optical energy to heat and to mechanical energy is responsible for the vibrat ion.

Infrared upconversion and optical storage thin film CaS∶Eu, Sm has been successfully developed by electron beam evaporation and radio frequency (rf) magnetron sputtering. Infrared upconversion efficiency of CaS∶Eu, Sm thin films with different thickness has been investigated by using the ultrashort infrared laser pulses with different FWHM. It is shown that upconversion efficiency of CaS∶Eu, Sm thin film not only depends on the growth conditions and the post annealing process, but also has the “exhaustion” phenomenon. By means of measuring transmittance and spatial resolution of CaS∶Eu, Sm thin film, the post annealing process was found to promote grain growth which could obviously improve upconversion efficiency of CaS∶Eu, Sm thin film, even though it had negative influence on transmittance and spatial resolution of CaS∶Eu, Sm thin film.

The spectroscopic properties and optical recording performances of a new spin-coated heterocyclic azo dye-doped PMMA thin film were studied. A strong and broad absorption band was observed in the region of 400～550 nm. The optical recording performances of the azo dye-doped polymer thin film showed that low power Ar+ laser irradiation could initiate a relatively high reflectivity change, indicating that the thin film is a promising optical recording medium.