This paper describes a diverging fibre that is analogous to a concave lens. The ray paths in the fibre and the fomulae for calculation of focal length, image distance, linear magnification and effective length of fibre are given.

It is pointed out that the additional a-o diffraction is caused by reflected acoustic waves, and this phenomenon is explained from the following aspects: the distribution of reflected acoustic waves (longitudinal and transverse waves), their intensities, the diffraction angles of light, and the difference of a-o diffraction characteristies between acoustic longitudinal waves and transverse waves for the plane-polarized light. The results of experiments are in accordance with the analytical ones. The author believes that using these phenomena, an effective method for checking sound absorption can be provided.

In this article we discuss the relation between the laser beam divergence and the amplification factor in unstable cavities and the principles for the design of unstable resonators are given.

The degradation phenomena of DH lasers operating at room-temperature have been observed. It is found that some lasers degrade in a short time and their differential quantum efficiencies decrease while the threshold currents increase. It has been demonstrated in aging test at elevated temperature that the life-time can exceed ten thousand hours if the thermal stability of a laser is good and the increase rate of its threshold current (△Jth/Jth 103 hours)within a longer peried(over 250 hours)is less than 3%.

Effects of C6H14 at different pressure on laser oscillation of CH3F at 496μm has been observed. The optimum result was obtai ned with a pressure ratio of CH3F: C6H14 = 1:2. Its far infrared output power is increased by 1.53 times compared with that of pure CH3F.

An efficient sealed sample cell for laser Raman scattering spectrum is described. It’s efficiency is about 100 times higher than that of the common cell and the experimental results are in agreement with those of computation.

This paper reports a recombination laser of xenon plasmas produced by CO2 laser excitation of gas mixtures of xenon and helium.

A stretching circuit capable of measuring peak voltage of a single ns laser pulse and the relevent test issues are described. The circuit has the features of simple structure, stable performance and broad dynamic range etc. Satisfactory results in CARS measurement with this technique have been obtained.

Public lecture of Shanghai Laser Society run every two years was held from September 22-24. Papers presented covered new results and progress in the field of laser science and technology.

In this paper we propose a new convenient and effective technology to fabricate plane-stripe lasers by using AlxGa1-xAs layer Zn-diffusion mask. Lasers have been fabricated by this technology, and the devices possess longer lifetime and better linearity.

YAG laser output at 1.06μm is stabilized with intracavity frequency doubling Ba2Na(NbO3)5 as a leakage compensation component. Controlled experiments have been performed on two CW-pumping sources with different accuracies. It is observed that all the amplitude of output noise spectrum have been notably improved.

New technologies using proton bombardment to form Ga1-xAlx AsGaAs DH lasers of stripe-geometry are described and our experimental resultsare given.

Four-mirror cavity is widely used in contemporary ring lasers or laser gyroes. The paper gives the methods for caculating cavity parameters and the frequencies of different modes. Practical examples are given on calculation and analysis of "8"-shaped four mirror cavity in a differential ring laser.

This paper describes the principle, design and construction of the GaAselectron-optic phase modulator. The expression for voltage has been derived on both ends of the modulated crystal as a function of matching circuit parameter and the output power of the modulating source. The measuring technique and experimental results are presented.

This paper introduces an infrared grating on metallic substrate and the testing methods. This kind of grating has been used in lasers.

In this article holographic testing method of separated multi-beadring of tyre is reported and the relationship between the interference fringes and the separation of bead-ring is discussed.

We treated adults of maize weevils (Sitophilus Zeamais Motschulsky) on wheat by a CO2 laser. The mortality of maize weevils reached up to 99.25-100%; it had no adverse effect on wheat germination; wheat moisture was decreased by about 1.7%; wheat color was normal and the grains had not been damaged after treatment.

Nd glass laser pulses have obvious destructive effect on the grafted S180 Sarcoma of mice. They have good effect in the clinical treatment of many kinds of skin cancer, Kaporis sarcoma and advanced recurred tumourous nodes. No metastasis due to the tumour sputtering was found both in animal experiments and clinical pathological observations.

Curative effect of 63 cases of acute otitis media treated with low power He-Ne laser has been observed, and the results are discussed briefly.

A brief account is given on the 7th Ail-Union Vavilov Conference on Nonlinear Optics.