Research of interaction faetween’light and atomic system of two energy levels enables us to obtain some important knowledge, such as transition probability of the electron. Usually these equations can be solved using the method of perturbation approximation in quantum mechanics. Direct study on the analytic solution of these equations has been conducted by many reseaehers, but so far no one has obtained a satisfactory and simple form of analytic solution. This paper presents some simple analytic equations of transition probability of the electron under several different conditions, including damping and strong field. It provides some convenient mathematical formulas for the study of electronic transition process.

Characteristics of infrared multiphoton dissociation of ethanol molecules were investigated experimentally. The dependence on dissociation rate on laser frequency, laser energy, pulse number, temperature and initial pressure are given. The maximum value of dissociation rate of ethanol molecules was found to shift by 8 cm-1 towards longer wavelengths relative to the peaks of its linear absorption spectrum.

We have observed a conical emission from sodium vapor (N-1014cm-3) illuminated by a near-resonant dye laser (detuning on the short-wavelength side of D1 or D2 line). Spatial, spectral and polarization characteristics of this emission have been measured.The results are compared with the experiments using barium vapor.

An instrument used for point by point analysis of laser speeklegram was designed and made in the lab. The principle of automatic fringe readout and data process is described. An example which uses this instrument in strain analysis is shown and error analysis is also discussed. This instrument facilitates the application of laser speckle technique.

Two mathods for the correction of astigmatic laser beam are proposed: Astigmatism can be compensated by controlling the sign of surface flatness or by inserting an inclined lens in laser system. General formula to calculate the astigmatism and compensating parameters has been derived. Theoretical calculation is in good agreement with the experimental results.

Five kinds of lithium rare earth tetraphosphate crystals (LiLnP4O12, where Ln represents Ce, Pr, Eu, Ho or Br) have been synthesized using high temperature flux method. Their physical and spectral properties have been investigated systematically. The study of the absorption and the fluorescence spectra of LiPrP4O12 shows that this crystal may be used as a promising laser material in the visible region.

The simulating experiment on hydro-acoustic effect of high energy charged particles by Q-switehed pulsed laser beams has been made. The influence of heat pulse waveform on the time structure and the amplitude of acoustic signls has been also observed and studied by means of a non-Q-switched pulsed laser. A comparision between our experimental results and the data of hydro-acoustic effect of charged particle beams generated by accelerator shows that the main experimental results from these two methods are consistent. Further application of pulsed laser technique to the study of high energy physics and cosmic ray physics are discussed.

Reports on the use of GaP prism coupler have been published abroad, but details of its structure parameters have not been given. We designed and fabricated prism couplers with GaP crystal in our country. Light beam was successfully coupled into and out of a Ti diffused LiNbO3 planar optical waveguide and the m line was observed.

The paper describes a holographic interferometer which can expand the area of test, and discusses the evaluation and definition of sensitivity for holographic NDT of tyres, also presented are the approaches for the increment of sensitivity.

In measuring laser performances of Nd:YAG crystals it is always found that there are different results (such as pulsed or CW laser efficiency, internal loss) for the same crystal rod at the same experimental conditions when the rod is rotated in the cavity. We consider that is caused by the inhomogeneity of the laser rod.The influence of optical homogeneity of Nd:YAG crystals on the laser output charaete-tistics was studied. Laser performances of crystal rods have been measured. It is pointed out that stable laser output can be obtained with optically homogeneous crystal rods.

The third harmonic of Nd-YAG- laser has been obtained by frequency summing with a peak output power of about 1.7MW is used to pump a dye laser, and the wavelength tuning range is from 409.3 nm to 682.3 nm. A peak power of more than 0.60 MW is generated at 450.0 nm, the center wavelength of eoumarin 47. When coumarin 152 is used alone, a broad tuning range of up to 104.2 nm has been obtained, which is close to its fluorescence linewidth of 120.0 nm.

A simple and reliable voltage controlling unit is added to the conventional resonance charging network and a compact power supply for pulsed solid state lasers is thus formed. It has the advantages of high efficiency and voltage adjustability over wide range. The features of the circuit are analysed and the experimental setup is given.

A simple method is introduced for the measurement of gas temperature in the positive column region of He-Ne gain laser tubes: a long and fine glass fibre is inserted into the capillary and the gas temperature is derived from the elongation of the glass fibre. Preliminary measurement results are given and discussed.

High-resistivity sicon switching is irradiated by picosecond optical pulses and "on" and "off" of opto-elecotronic switch is thus achieved.

Holography for nondestructive fault detection is a technique developed in recentyears. Reported in this paper are a group of experiments using double exposure laser inter-ferometry-way of vacuum and increased pressure to test automobiles tyres, as well as thediscussion on defect analysis in terms of interference fringes. The result shows the feasibilityof laser-interferometry in the test of rubber products.

This paper reports the results of trimming thin or thick film resistances with an aeousto-optic Q-switehed YAG laser.

22 cases of chilblain were cured by local irradiation with He-Ne laser and the curative efficiency reached 100%.

73 cases of alopesia were treated with He-Ne laser and the curative efficiency reached to 85%. Some factors affecting the curative effect are presented.

We used a He-Ne laser of 1-2 mW to treat 23 patients of macular hole and retinal detachment with macular hole, totaling 28 eyes with therepeutie rate of 92.86%, no decrease in vision and no complication occurs.

This article reports the treatment of prostate hyperplasia witha He-Ne laser. It has good effects on the improvement of urinary symptoma and reduction of prostate hyperplasia.