Langmuir flow effect in a D. C. discharged ring laser is one of the important factors causing zero drift. The employment of linear cavity tubes in the ring cavity is discussed.

The configuration and technology for proton bombardment stripe geometric GaAs-GaAlAs DH laser is described briefly. The performances of DH laser under DC forward current were measured and analysed. The threshold current of most lasers is 50-150 mA. Differential quantum efficiency ηd is 30-70%. Some lasers operate in single transverse mode and near single longitudinal mode. The degradation properties were studied and the lifetime for some lasers are over 5000 hours.

The parameters of the optically pumped far infrared laser have been calculated. The configuration and oscillation characteristics of the first optically pumped far infrared laser in our country are described. Transmissivity of far infrared optical materials at 496μm, such as fused quartz, germanium, silicon, polyethylene, polytetra-fluoroethylene and all kinds of papers etc have been measured by the methylfluoride far infrared laser and the data are given.

The experimental setup, test method and laser performances at room temperature for a neodymium pentaphosphate laser with a single transverse mode longitudinally pumped by a dye laser at 0.58μm are described. The optical slope efficiency is -10%, threshold energy for single transverse mode is -40μj. Oscillation threshold for single mode of longitudinal pumping was estimated with a simple computer model. They agree each other within the experimental error of 10%. A single pulse without Q-switching can be obtained by appropriately varying the cavity parameters.

A simple high repetition rate molecular N2 laser is described. Experimental results for the laser operated at I atm. are given. The dependence of electrode spacing on the threshold charging voltage were measured. It was found by the experimental investigation on relations between the output power and the charging voltage with different electrode spacing (0.8-2.2mm) that a certain output power can be obtained at low operation voltage with narrow spacings. Many kinds of dyes were pumped to produce laser output at the voltage of 8kV.

The experimental investigations on Q-switching of a ruby laser system by cryptocyanine are reported: 1) The dependence of output characteristics on dye concentration and other parameters of the laser cavity, 2) the dependence of output energy on temperature and solvent of the dye, 3) the influences of temperature, solvent and impurity content on the optical bleaching of the dye solution. Theoretical analysis and numerical tests are made for the third problem on the basis of the experiments.

Influences of electric domains on the optical homogeneity and electro-optic properties are discussed for the purpose of improving crystal quality and performances of laser devices. The extinction ratio at dynamic and static states are discussed at first, then the influences of the electric domains on the optical homogeneity and the Pockell’s effect.

The method of selectively "pruning" the intraeavity signal is employed to produce a clipped pulse inside the cavity. The cavity subsequently behaves as a regenerative oscillator through amplification of this clipped pulse. Nanosecond pulse trains have been obtained with this technique.

The technique of obtaining a 3×10^4 Gauss pulsed magnetic field is described in detail and experimental results of 1.06μm, 60mm magneto-optic isolators are given. It had been measured that when a multi-layer dielectric film polarizor was used, the extinction ratio of the magneto-optic isolators was larger than 5×10^2.

The effects are considered of spectral bandwidth and slit width on holographic Fourier-trasnform spectrum with quasi-monochromatic light illumination in using the Fourier-transform method. Theoretical analysis shows that the original distribution of spectral intensities is changed in the process.

Development process of coaxial pulsed xenon flashlamps both at home and abroad is reviewed. Configuration, test of performances and results of coaxial pulsed xenon flashlamps and comparison with linear pulsed xenon flashlamps are given.

73 eases of malignant tumour were cured by an adjustable three folded CW sealed-off CO2 laser with a power density of 105-333 W/cm2 at the "knife head". The 2-year survival is 76.7 %. Clinical practice shows that laser evaporation of malignant tumour do not results in sputter ing and proliferation of cancer cells, and it is also effective for the later period hopeless cases, so it has advantages in comparison with conventional treatment methods.