Using the hydrodynamic model we have derived a unified expression for oscillation frequency of an optical cavity. It is as follows:and it has been tested with several examples.

The new planar-continuum potential, the sine-squared potential, is introduced to analyse the behaviour of particle motion in a planar channel, and particle motion equation is written by the well known pendulum; particle motion equation and oscillation period are solved exactly by Jacobi elliptic functions and the first kind of complete elliptic integrals; radiation intensity and spectral characteristics of Kumakhov radiation are further analyzed; The results show that it is possible to take Kumakhov radiation as a new y-ray laser.

Using a mode-locked laser at the wavelength of 0.53 ℃m with a peak power of over 107 W, we observed Stokes waves of fifteen orders and anti-Stokes waves of eight orders in a glass fiber with the composition of Ge-P-Si and a length of 20 m. The Raman frequency shift is 430 cm-1 in wave number, the range of frequency spectra of the scattering light covers from 0.45℃m to 1.00 ℃m. The conversion efficiency of the Stimulated Eaman scattering is higher than 50%.

Multiple imaging by phase grating has the advantages of better image quality and higher efficiency campared with other methods. A method of scanning-exposure was suggested, triangular phase grating was made up by this method. Its principle and experimental results are presented in this paper.

The F2-centers of LiF crystals have the lowest energy level. The optimum dosage-rate of γ-irradiation for obtaining high density F2-centers has been investigated experimentally. The F2-centers are bleached after 6,200 shots.

This paper presents an experimental device for simultaneously tunable operation at two wavelengths, using a single rhodamine 6G cell pumped by a nitrogen laser. The experimental setup and output features are given.

A new form of two-wave SRS is discovered using two nanosecond-pulsed laser beams of different frequencies to irradiate calcite and benzene when the frequency-difference of the incident beams is in resonance with the Baman transition frequency of the sample. The conditions for this phenomenon and characteristics are investigated experimentally. An essential explanation is the resonance-coupled two-beam self-focusing.

A double exposure holographic interference method for distribution measurement of refractive index in optical glasses is reported. The measurement accuracy is ±1×10-6.

The beat frequency between modes of optical resonator with concave mirrors have been studied by the photomixing technique. In the experiment He-Ne laser(6328A)and Ar+ laser were used. Based on the random variation of cavity length, characteristics of the medium index and mode competition effect, low-frequency beat and noise continuums are explained.

We present here a new method for heterodyne bias frequency locking of tunable lasers and give the expression of the locking precision caused by the frequency instablity of local signal source. In the experiment we use two CO2 lasers locked each other, and dicussed the potential application of this technique to the measurement of short-term frequency stability of laser in different laser frequency spectra.

We prepared a two-wavelength antireflection coating with three layers of equal thickness. The residual reflectivity achieved is 0.1-0.2% at the wavelengths 1.06 μm and 0.53μm.

When a mirror with a small hole is used in the CO2 double wavelength laser the tunable range is broadened. The temporal and spatial characters of the laser and the relationship between the wavelength tunability and the CO2 laser parameters are studied.

An apparatus using TP801 microcomputer for measuring laser polarization degree is described. The relative measurement error is about 3%, and the uncertainty is less than ±10%. Any other laser parameters can be measured by simply changing the subroutine of the system.

The histological change of 100 removed uterus and parametrium specimens by laser photovaporization have been observed. It has been found that the small myoma and solitary adenocarcinoma within the uterian cavity can be removed by vaporization, but the tissue damage underneath the burned layer is the minimal. The experiment suggests that YAG laser is safe and practical in gynecological surgery.

Reported here are the treatment method and curative effectiveness using low He-Ne laser needles.

This paper reports the penetration test on the living body with a low power He-Ne laser. The penetration depths of 25 mm in two layers of skin, hypodermis and muscularis, have been achieved.