Preionization conditions for the homogeneous formation of pulsed avalanche discharges without considering the voltage rising-time of electrical pulse are discussed. The results are in good agreement with the experimental data obtained by V. N. Karnyushin et al.

This paper analysed the limitations of resolution of ultrasonic detection and presented a method of optical computing real-time processing for ultrasonic pulse-echo.

This paper presented six absorption lines of NH3 molecule in 1.5 μm band. The absorption profiles of the 1.5361 μm wave length laser in six different absorption cell are observed and compared the calculated half linewidth with the experimental value. At the same time the absorption profile and its differential profile of the 1.53735 μm laser passed through an absorption cell filled with NH3 molecule with the barometric pressure of 2.79×103 pa are also observed. Using the results the frequency stabilization can reach 1 MHz.

A hew method to analyse the mode of axially-asymmetric optical resonators is proposed. The algebraic equations for the sizes and the locations of the beam waists of the ellipse Gaussian beam, as well as the stability condition are obtained. This method has the advantages of simple, easy and universal validity.

The propagation of arbitrary temporal amplitude profile optical pulses through it dispersive media is discussed by using matrix method. A pulse quality factor M2, and a generalized complex pulse parameter P-1 is introduced. The generalized ABCD law for arbitrary pulses with any amplitude shape and any chirp through dispersive systems is derived.

This paper proposes the new method of making image color hologram and reconstructing this kind of color hologram with white-light. According to Kogelnik's coupled theory of thick hologram, the angular sensitivity of the volume phase hologram is very high, while its wavelength sensitivity is rather low. Making use of this,three primary color reference beams can project on the holographic plate along different orientations respectively in accordance with the requirement of the angular sensitivities. When the hologram taken by this method is illuminated by the three primary color general light beams whose spacial frequencies are equal to the three primary color reference beams respectively, the three-dimensional true color holographic image of the original object will be reconstructed with the cross-talk removed. Using three holographic gratings to select the three primary wave bands from white-light for reconstruction and compensating for the dispersion of the color hologram, this kind of white-light reconstruction method can obtain three-dimensional color image without color blur.

The distributions of Amplified Spontaneous Emission (ASE) in the Dye Laser Amplifier (DLA) as well as the excited level and triplet state populations of the dye have been reported. The store energy of dye molecules and the amplification of fs pulses in condition of under saturable energy were calculated by mathematical simulation. According to our analyzing, the decreasing of store energy caused by triplet state absorbing must be taken into account when designing a DLA. Experimentally with Q-switched Nd:YAG synchronouly pumped two-stage dye laser amplifier, we have got the amplification gain of 1000 and 60 for the first and the second stage respectively. To the first stage, our calculation result can be fit well with the experiment.

This paper presents the experimental results of Cr:Mg2SiO4 tunalbe pulsed laser pumped at room temperature by the fundamental 1.06 μm pulses from a Q-switched Nd:YAG laser. The wavelength range can be continually tuned from 1.167 μm to 1.332 μm. The output energy of 11.5 mJ and coversion efficiency of 16% have been achived. Tunable laser output from 0.584 μm to 0.666 μm was generated by frequancy doubling from the Cr:Mg2SiO4 laser.

Self- frequency doubling NYAB laser crystal was pumped by quasi-continuous Ti3+:A12O3 laser and green laser output at 0.531 μm was obtained. Its average output power and total efficiency are up to 27.6 mW and 22.6% respectively.

Single- quantum-well GaAs/AlGaAs laser with graded- index separate confinement heterostructure (GRIN-SCH-SQW) were fabricated by molecular beam epitaxy. The laser exhibits low threshold current and single mode operation performances. 55 mW/facet CW output power has been obtained.

Using NaCl(OH-):(F2+)H color center crystal made by authors as laser medium, the low temperature infrared tunable CW color center laser operation has been realized successfully in the X-model laser cavity, with tunable laser wavelength from 1.40 μm to 1.75 μm and its peak wavelength is at 1.57 μm. Some problems such as several absorption bands of (F2+)H color center, the relation between color center laser output and laser medium, as well as auxiliary light have been discussed in this paper.

Based on the rate equation we have analysed the Q -switch mechanism in the Nd:YAG phase conjugating laser with the SBS cell and established a theoretical model for the Q-switch process. With the numberical calculation we have got the relationship of photon density versus time. It is in good agreement with the experimental values.

The soft X-ray spectra of Na-like Ge ion of ls22s22p6nl(n=3-6,l=0 -5) configurations for dipole-allowed transitions are computed with the aid of the HFR program with the optimization of Slater paramters on the basis of the known experimental levels. The excellent agreement between the calculated wavelengths with the observed ones is obtained and these results are discussed.

Refractive indices of LiNbO3:MgO(5mol%) at room temperature have been measured by the auto-collimation method. Based on these refractive indices, we obtain the relationship between type I phase matching angle and the wavelength. Then use it to calculate the phase matching conditions at 1079.5 nm and 1341.4 nm. The reliability of the results has been verified by 1079.5 nm and 1341.4 nm Nd:YAP pulse lasers. The errors between calculated results and experimental results are less than 1°.

Persistent spectral hole-burning is reported for the organic guest molecule 5, 10, 15, 20-tetra-(p-methoxyphenyl) porphin (TMP) imbeded in polymethylmethacrylate (PMMA) host at liquid helium temperature. The effects for power saturation of hole depth and power broadening of hole width were observed. Hole growth dynamics was investigated and the process of light induced hole erasing was measured. Theoretical fits to the experimental data were carried out and hole burning mechanism of the system was discussed.

Amplification characteristics of four-level fiber amplifiers are analyzed using four-level system rate equations. The relations of the signal gain against fiber length, doped ion concentration, pumping power and signal power are obtained and calculated.

A new type of RF excited all- metal waveguide CO2 laser is presented. Its output characteristics are studied and compared with those of metal-ceramic sandwich and naked metal waveguide structures in the same geometrical size. With this structure, we have obtained 12 W EH11 waveguide mode output power from gain length of a 300 mm.

Two-wave coupling in photorefractive media leads to intensity-dependent phase shift as well as energy transfer between the two waves without phase interdisturbance with this mechanism, the theoretical and experimental study on the optical gain oscillation has been done by using an optical ring cavity containing photorefractive media. The experimental results agree with the theoretical analysis.