A new method for calculating selected frequency and linewidth of a passive cavity for pulsed dye lasers is presented. Several typical cavities containing gratings, etalons and resonant reflector as frequency selective elements are studied. The influence of groove number of gratings and the optical thickness of the resonant reflector upon linewidth are discussed. The theoretical values are in agreement with the experimental results.

Molecular Stark effect in NH2D is used to modulate strong P (20) line at 10.6 pm of a CO2 laser. A modulation depth of 41% is obtained from a 400 Hz 20V rms sinusoidal modulation signal and a 440 V DC bias applied to a 20 cm gas cell outside the laser at a gas pressure of 5 torr. The maximum modulation depth of the gas cell is calculated as 42%, which is in good agreement with the experimental result. When sinusoieal modulation signal is 2 MHz 20 V rms, a modulation depth of 12% is achieved. NH2D was prepared by mixing ND3 and and ND3 was prepared by the present authors.

A TEA CO laser operating at room temperature is reported. The output characteristics were studied. For CO:Ar (1:1)mixtures; the maximum output was 5 mjat a total pressure of 160 torr, and the peak power was approximately 3.6 kW. The output energy of the sealed-off TEA CO laser was essentially stable after over 105 shots.

Ternary Ga1-xAlx.As is changed into quaternary Ga1-xAlxAs1-yPy compounds by two liquid phase epitaxial techniques in making GaAs-Ga1-xAlx As double-heterostructure lasers. The results measured by x-ray diffractometer show optimal GaAs-Ga1-xAlxAs1-yPy heterostructure lattice mismatching is decreased down to 1x10-5, the relative mismatch stress is 1.4X107 dynes/cm2. Observation with scanning electron microscope shows that the heterostructure interface is very flat. This method can significantly improve the heterostructure quality. Double heterostructure semiconductor lasers with efficient, long lifetime can be expected.

It has been found experimentally that the planar stripe lasers with deeper Zn diffusion have more stable horizontal transverse mode. A simple equivalent circuit model is proposed that can explain why the planar stripe lasers with deep Zn diffusion have stabilized horizontal transverse modes. It is shown analytically that the narrowing of gain-induced guide of planar stripe lasers .with undoped active layer and deep Zn diffusion is responsible for the stabilization of the horizontal transverse modes.

This paper deduces the threshold condition of semiconductor lasers analytically with the electric-magnetic wave theory in a slab waveguide model. It is found that the expressions of the threshold condition for TE mode and TM mode are different from each other. In the formulas deduced here there appears a revision factor as compared with the conventional formula, which can be explained with a point of view of zigzag waves.

We report here the enlargement of tuning range with the multicomponents of PPOPOPOP scintillators. It has been shown that the enhanced fluorescence band at 3600~4200A range can be obtained by varying the concentration of PPO:POPOP. The mechanisms for non-radiative energy transfer and the dipolar relaxation will be further studied in detail.

Many kinds of optical gyros based upon the Sagnac effect have been constructed. Their fundamental precision limits are discussed and compared in this article. Some practical problems are also presented.

In this paper the principles, prospects and potential applications of phase conjugate optics, in particular degenerate four-wave mixing, are reviewed.

A 3 cm X-band microwave interferometer with a phase-locked amplifier as detector has been used to measure small phase changes as a microwave beam passing through the gas discharge tube.The influences of adding N2, He, Xe in the discharge tube on electron density are studied.

This paper reports a He-Ne laser at 3.39m emitting visible light (A=0.6328m) with additional mirrors.

Principles, applications and development of optogalvanic speetroscopy is briefly presented. The optogalvanic effect in a neon buffer and sodium sample has been measured using a pulsed dye laser at the wavelengths ranging from 5800 A to 6200 A.

1-bromopropane has no adsorption band in the frequency range corresponding to the p-branch of 001~100 transition of CO2 molecular, so that multiphoton dissociation does not occur. However, as a certain quantity of boron trichloride is added ,1-bromopropane will dissociate easily.

Basic research on the characteristics of optical spatial filters have been performed, and the principles on selecting shapes and dimensions of pinholes are given. On the basis of appropriate usage of spatial filters, dependence of wavefront coherence on the focusable power have been found.

This paper introduces briefly the effects of laser irradiation on rice with different wavelengths and doses, variety characteristics, and the effects of complex treatment with laser and 60Co gammarays on the variation rate of rice L2.

This paper describes some issues of the principles and construction of LCA laser calorimeter.