A new technique for cooling and trapping gas atoms and molecules is reviewed in this paper. This technique is a new important direction for the development of laser applications. It will provide a powerful tool for the researches on spectroscopy, atomic frequency standards and atomic physics. It seems that this technique should have wide applications in some other research fields.

The laser system in our experiments consists of a Nd:YAG oscillator and three Nd:glass amplifiers with diffraction-limited output beams. Crystals for frequency doubling are KDP and KD*P. When unfocused collimated laser beams were used in frequency doubling, a maximum energy, conversion efficiency of 65% has been obtained,the corresponding peak power conversion efficiency was about 84%. In the case of low laser power, by means of cylindrical focusing laser beams, energy conversion efficiencies were increased by a factor of 8 to 30 with a maximum conversion efficiency of 64%.

In the high power segmented CW Nd:YAG laser concave surfaces ground directly on laser rods have been employed to compensate the thermal focusing effect. We have obtained experimentally 100~150 watts output power in less than 10mrad from a laser of two Nd:YAG rods in series.

Branches of a CW CO2 laser were selected by a tunable complex-cavity composed of an ordinary glass-substrated grating. High power output up to 42W with definite direction and location for the branches were obtained with high gain. The number of branches is dependent on the parameters of the camplex-cavity. Basic principles and experimental results on tunable complex-cavity are described.

Coherent anti-Stokes Eaman spectroscopy provides distinct advantages due to its high efficiency, high resolution, suppression of back-ground fluorescence and coherent anti-Stokes character. An experimental arrangement employing two dye lasers pumped by a single nitrogen laser has been set up for CABS and the output signal is detected with photomultiplier and boxcar integrater. Spectra of benzene, toluene and a series of halogen substituted benzene derivatives ia the vicinity of 1000cm-1 have been measured.

This paper discusses the change of discharge properties due to mismatch effect between transmission line and discharge impedance in electron beam controlled discharge gas lasers.

It is proved in a complicated optical system that the diffraction integration in terms of ray matrix element is the right solution ’for paraxial equation. This is used to investigate Gaussian beam and resonator modes and some new results have been obtained.

We have produced ohmic contact on the surface of n-GaAs using a pusled Q-Switched ruby laser (A=0.6943m), a pulsed Q-Switched YAG laser(A=1.06m)and a frequency doutled pulsed YAG laser (A=0.53m). The specific contact resistance of alloyed Au-Ga-Ni contacts has been measured on the surfaces of n-GaAs. The experimental results show that the use of laser alloying forms more uniform ohmic contacts. The contacts possess electrical properties and surface conditions which are superior to those formed by conventional bulk-heating.

A new method is introduced for the measurement of percentage modulation for ultrasonic light intensity modulator by means of low frequency modulation. Difficulties arising from conventional photo-electric mesurement systems in the simultaneous measurement of D. C. and H. F. alternative components may be overcome. D. C. components of the photo-electric signals and a low frequency signal whose amplitude equals to 1/2 of the HF alternative components are displayed on an oscilloscope so that the rigional definition of percentage modulating can be used to calculate its percentage modulation.

A prototype was developed and put into operation in factory for the measurement of optical fiber diameter by forward scattering light with He-Ne laser as light source.

In this paper, fundamental principle and method for measurement of distributed inductance of pulse capacitor by means of resonance method are introduced. Through proper transformation, the present method can be used to measure distributed capacitance of inductance coil too.

A bulk absorption solid calorimeter with neutral coloured glass as its absorber has been developed. It can be used for the energy measurement of laser pulses whose wavelengths range from 0.4m to 1.1m and energies 1 joule to 50 joules, with an absolute accuracy of 5%. The calorimeter is calibrated by electrical heating, with a calibration reproducibilily of better than 0.5%.

This paper compares the effectiveness of laser, cryosurgery and microwave in the treatment of advanced recurrent breast carcinomas and sarcomas. An effective rate of 37% (17/46) has been found. Of which 3 cases have no evidence of recurrence for over 2 years, 2 cases over 1 year. On the basis of the anti-cancerous mechanisms of the three physical methods of therapy, the authors discuss the merits and indications of laser as compared to the other two methods.