Reported here is a new technique, rotation speed-controlled layer thickness monitoring, which can accurately monitor very thin layers for soft X-ray mirrors. Three W/C multilayer (d=10 nm,30 periods and d=8.4nm, 50 periods)are fabricated and characterized by low -angle X-ray diffraction. The results show that the random error of the periodic thicknessis being about 0.1nm.

A wavelength separation filter glass is studied for Nd3+ glass laser frequency-doubling. The transmission is less than 10% at the central laser wavelength (1053nm) and over 87% at the visible wavelength (530nm).

The effect of moist ability between the materials and the laser cladding quality of preconditioning layer are investigated. The materials with good moist ability for other materials have the surface layer without holes and eracks, whereas those with the poor moist ability may have surface layer of faults.

Extinction ratio test is adopted directly to cheek the sensitivity of pulsed laser rangefinders and the influence of weather and the limilation of terrain are eliminated effectively by analysing the test data and comparing them with its measurement range quantitatively.

The genetic effect of two stocks of D. melanogaster, C. S., Base, were studied with irradiation from CO2 laser. Experimental result shows that when the radiation dosage of CO2 laser amounted to 69.5 J/cm3, the genetic effects of recessive lethal mutation is distinctlyhigher than those of the contrast.

Canine femurs were ablated with an Er:YAG laser (2.94μm) with a pulseduration of 250μs. The bone ablation characteristics at four difierent pulse repetition rates (l-4Hz), were studied. The ablation depth versus energy density per pulse seems to follow an exponential function for large range of energy density. The increase of ablation ratio versus energy density at 1Hz was the highest, 2Hz the second, when the energy density levels were less than about 100 J/cm.

The principle and technique of real-time pseudo-color encoding for optical density images using a liquid crystal light valve(LCLV) are described and a simplified hybrid field effect mode of LCLV is presented, the polarized modulation of linear polarization readout light passed through liquid crystal layer is mathematically analysed, and the relations between the projection intensity and the voltage on the LC layer, the polarization direction and the wavelength of the readout light are given. With these results, the principle and essence are discussed in detail. Experiments show that our analysis method is effective. At last, some pseudo-coloring images are presented.

holography; phase-conjugate; assceiative memory

A new technique of multi-slit one-step rainbow holography with multiexposure holographic lens is described. The theoretical analysis for the holographic parameters and the experimental results of image color addition and subtraction are presented by means of this technique.

The statistical properties of the integrated intensity fluctuation of the noncir-cular Gaussian laser speckle formed by atmospheric scattering is discussed. The general formula of the probability -density function of the laser scintillations in the turbulent media and the K distribution probability-density function of the integrated intensity of the laser beam propagating in weak turbulent fluctuation region are obtained.

The steady state model of two-photon optical bistability in narrow-gap semiconductors are presented. The steady property of dynamic optical bistability in InSb and HgCdTe are analyzed and the ideal pulse shaping effect is obtained experimentally.

A gas laser with a refrigerator is reported and its operation characteristics are investigated.

A novel composite circuit power supply with double voltage and full-wave rec-tification for CO2 lasers are developed. With this power supply, the CO2 laser outpat not only car be adjusted continually from zero to full power, the CO2 laser can also work in CW or puise mode. The fluctuation of average output of the CO2 laser is less than ±5%.

The main spectral properties of Li-like Si soft-X-ray laser are examined theoretically based on the relevant experimental study (Xu Zhizhan et al., Chinese Journal of Lasera, 16 (10), 616(1989)) and the most probable pumping mechanism for this laser is suggested.

Diffraction efficiencies and parameters of pinhole transmission gratings are determined using L-band (1.15 nm) characteristic line emission from copper laser-plasmas. Features are reported systematically of experiments with the pinhole transmission grating spectrometer in laser plasma soft X-ray radiation investigation.

Spectral supercontinuum of high intensity ultrashort-pulse propagating in a non linear medium is calculated directly by solving the nonlinear-wave equation based on the cubic nonlinearity. When the dispersive effect and the steepening effect are excluded, the result yields an asymmetric Stokes-anti-Stokes supercontinuum, which agrees quantitatively with the experiment of Fork et al.

Stimulated radiation based on Na-Na near-resonance collision energy transfer has been observed in the sodium vapor. The stimulated emissions from 4f or 4d level of atomic sodium are generated via two-photon resonant excitation of 4d level or dipole-forbidden two-photon resonant excitation of 4f level respectively and the related processes are discussed.

Experimental setup for studying the generation of backward stimulated Raman, scatering pulses in ethanol and the experimental results are reported. The pulsewidth of the shortest Eaman pulse is 280fs with a compression factor of 100.

Selectivity and excitation rate of laser isotope separation can be enhanced by using the coherent selective Doppler-free two-photon excitation with intermediate resonant level. Analytical solution of Bloch equations about this process has been drived. The results of level-population, excitation rate and selective coefficient have been obtained.

Experimental research on the phase conjugation by SBS in a laser resonator using saturable absorber as SBS medium is reported. The result shows that the threshold of laser and SBS will decrease, the light beam quality and its efficiency will be improved greatly. The experimental results are discussed.