A theoretical model of dual beam thermal lens effect is derived. The model predicts the intensity distribution and variation in far field of the laser beam in the presence of weakly absorbing medium. Some experimental results which support the validity of this approach are presented.

The theory on optical coherence modulation using 2-D ultrasonic standing waves is reported and corresponding analyses are made. Theoretical results show that when 2-D ultrasonic standing waves are used, the phase difference between two ultrasonic waves (i. e., correlation coefficient) with the same frequency and correlated phase has strong influence on modulation of coherence degree and that effect is small when ultrasonic travelling wave are nsed.Also reported are the preliminary measured results on coherence degree modulated with 2 D ultrasonic standing waves excited by two cross electrodes and AO-EO resonant coupling effects of LN EO-crystal respectively. The results agree with the theoretical analysis.

In this paper the pumping of a two level system by nearly resonant polychromatic field is discussed. It is pointed out that owing to the interference between field, one can obtain greater population inversion in the case of pumping by a monochromatic or dichromatic field. For the case in which the upper level splits into two nearby ones, the method of density matrix is used to calculate the steady-state solution for various parametric values. It is found that population inversion can be obtained at definite conditions.

Anomalous saturation for a backward Raman amplification with forward scattering feedback in H2 at high pressures is described and compared with a theoretical model.

This paper presents a new method of making white light reconstructed hologram with two orthogonal cylindrical lenses. A brief account of the method and the results of experiments are also presented.

A single longitudinal mode 35MW TEA CO2 laser system tuned with grating has been established. It consists of a hybrid TEA CO2 oscillitor and two TEA CO2 amplifiers, output pulse energy of 4.2J in a 120 ns pulse length, output power of 35MW and 81 tunable spectral lines have been obtained.

A CO2 -waveguide laser tuned by a grating compound cavity was investigated. The laser operated at more than 63 emission lines and the maximum single line power is about 1W. The theory of the compound cavity was analyzed. The experimental results are consistent with the theory.

A new method has been demonstrated in which the amplified beam is no longer coaxial with the oscillation beam. Thus, it extracts energy from different part of the laser rod. A laser beam with Gaussian profile and high power has been obtained. The requirement for optical uniformity of laser rod is not critical.

Wavelength tuning, linewidth and beam spread characteristics have been studied by using a long pulse discharge XeCl laser with grating, prisms and etalons as the intracavity mode-selecting elements. The laser output with the energy of 2 mJ per pulse, narrow linewidth (-10-2A) and diffraction limited devergency (-0.15mrad) have been obtained in our experiment.

The absorrption spectra, fluorescent spectra and fluorescent lifetime of Li-La phosphate glasses are measured. Radiative transfer of energy between Cr3+→Nd3+ ions in Li-La phosphate glasses are studied. Energy transfer efficiency from Cr3+→Nd3+ ions in Li-La phosphate is 38%, the optimum doping concentration of Nd3+is 2×1021cm-3 and Cr2O3 content is ≥0.1 wt%.

A two-wavelength (λ1=632.8nm, λ2=488nm) Mach-Zehnder interferometer was used to determine the distribution of the electron density and temperature in argon plasma jets. The results are compared with those obtained by using single wavelength interferometry.

The polychlorotrifluoroetlylene oil index matching fluids were studied and their performances, such as refractive index, absorption, isolation, breaking load and stability measured. The results showed that they can match KD*P crystals much finer than other kinds of matching fluids. The ref ractivity at crystal interfaces was improved by over 20 times and transmissivity increased over 10%. The fluid can be used to match calcite prism and good results were obtained.

A microcomputer-controlled double-probe system and the software for computing the electron temperature from the V-I curve measured with this system have been developed. At different discharge currents, gas pressures, ingradients of gas mixture and probe position of the 2kW CW CO2 laser, the measured average electron temperature and electron density are in the range of (1.7-3.2)eV and (0.62-1.36) ×1011cm-3 respectively. The E/N is about 2.0 × 10-16 V cm2.

Variations of mode intensity spectra of a semi-intracavity He-Ne laser put into an axial magnetic field at higher total gas pressure were invest’gated. A conclusion different from the previous ones was obtained. The experimental phenomena are explained based on strong competition effect between modes.

A train of ultrashort pulse at 530 nm and 1.06μm was focused into a 16cm long liquid cell. The measured spectral broadening and stimulated Raman scattering of polychloro-trifluoroethylene shows it is a very good index matching liquid.

No bacteriostatic effect on staphylococeus, colon bacillus, bacillus pyocyaneus, and streptococcus hemalyticus are observed with He-Ne laser irradiation (4-12mW/cm2) for 5-30 minutes.