The extension of vibrational relaxation equations to the case of degenerate vibrational modes is given and the meaning of viberational transition probability and the applicable conditions for the equations are discussed.

Single-branch oscillation of CO molecular laser at room temperature by a grating is reported. The maximum output of 5 W was obtained.

A low noise 3.39μm He-Ne laser with quartz discharge tubes of separate sections is developed. Compared with the device of ordinary quartz discharge tubes, the noise levels of laser output modulated by environmental noise and discharge current are suppressed by 20 db. The output characteristics of the laser have been improved obviously.

Experimental results of a copper vapor laser are reported, in which copper halide is used as lasing material. Maximum output of 72 mW was obtained when the laser operated continually for over 3 hours each time with a total operating time of 30 hours by using a sealed tube of 28 cm active length at the discharging pulse frequency of 14 KC. In addition, laser output is obtained by discharge of double pulse with two ball gaps. Finally, applicability of copper vapor laser is discussed.

A Cu II laser operating at 7808 A has been developed to study the discharging characteristics of hollow cathode and the discharge of copper hollow cathode.

A reconstruction method of holographic images is described in which a field lens is used to image the hologram onto the pupil of the eye, to enhance the intensity of the image without reducing its resolution, two holograms recorded at different directions are viewed by two eyes respectively to increase its parallax. Eecording hologram by using normal 35 mm film has an advantage of reducing anti-vibration requirement, however,the information is sufficient for viewing.

Kinoform has its own advantages in comparison with computer generated holograms. The principles, characterstics, applications of kinoform and the experimental results are discussed in this article.

An improved optical system is presented winch can record two groups of independent fringes simultaneously. The stress patterns of the bed of Diesel engines’ main bearing are shown. This system not only simplifies the measurement of static stress, but can also be used for studying dynamic stress.

A CO2 laser photoacoustio spectrometer has been designed and established. It has been used to determine ethylene, propylene, ethylene trichloride, 1, 3-butadiene and unsymdimethyl hydrazine, the concentration range is 1-200 ppm. This method is quite simple, sensitive and fast.

Hexagonal single block LiNbO3 electro-optic Q-switches of various sizes were designed. The performances of such Q-switches have been improved greatly in comparison with those of double 45° single block LiNbO3 electro-optic Q-switches. Its extinction ratio is square times of that for common electro-optic Q-switches, the efficiency is one time higher and the insertion losses are decreased.

LiTaO3 detectors for weak laser signals and pyro-eleotrio detectors for coherent radiation were developed. The area of device and the effect of heat transfer of substrate on the frequency spectrum of device noise are discussed. Some practical applications of pyro-electric detectors in laser technology are given.

Growth of nonlinear optical material-cesium dihydrogen arsenate singlecrystals from aqueous solution by modified falling temperature method is reported. It involves synthesis of cesium dihydrogen arsenate, preparation of seed crystals, conditions and parameters for crystal growth, growth of large cesium dihydrogen arsenate single crystals and the effect of pH value for CsH2AsO4 solution on taper angle (φ) of crystals.