Four analytical expressions, different in form but equivalent to each other, of flat-crystal X-ray spectrograph are presented. Several methods of wavelength determination without reference wavelengths are proposed.

Infrared dichromatic polarizer made of thin calcite for narrow band is developed, which are of high transmittance high extinction ratioes and larger acceptance angles in certain regions. Their extinction rat'o and transmittance are better than those of any other polarizing devices in the wavelength range of 3.35-3.55μm and 3.8-4.1μm for the plates of 1mm thickness.

The structure and the property of the optical system for composition and propagation of four laser beams are described and the measurement results for the degree of composition and the efficiency of propagation are given.

A new fabrication technology of K+-ion exchange buried waveguides in glass substrates is presented for the first time, which includes two-step ion exchange processes in different chemicals. The processes are simple, feasible and unnecessary to apply electric field. X-ray energy spectrometry analyses show the guides are buried ones.

Using a new diagnostic system composed of an argon laser, optical multichannel analyzer and fiber optics, the authors have detected the autofluoroscence spectra with porphyrin specific peaks from all of twenty three eases of oral cancers and seven out of eight premalignant legions as well as from some benign tissues. The cases of false positive and negative diagnosis are described and the identification for them are discussed.

Experimental results on the welding of low alloying steel (18CrMnTi) and 45 steel with 3-5kW CO2 laser are discussed. The depth/width ratio being about 2, the maxium penetration depth is about 5.5mm. Various technological parameters influencing the effect of laser deep penetration are studied and some effective measures for overcoming the defect (crack, gas hole) of aser deep penetration welding have been found.

The microstructure, corrosion and corrosion fatigue properties of 40# Cr steel irradiated with a 2kW CO2 laser beam have been studied using optical and scanning electronic microscopy. Experimental results show that the increase of corrosion resistance of materials depends on the laser irradiation parameters. The corrosion resistance of specimens treated with laser transformation hardening is better than that of the specimen treated with laser melting-resolidification, and the corrosion fatigue life time of the specimens irradiated with laser is 2.58~6.94 times that of the unirradiated ones, and the corrosion resistance mechanism, the characteristics and mechanism of the corrosion fatigue of the materials are analysed.

Investigation results of laser remelted alloying processing of A3 steel sprayed with NiCrSiB powder are reported, and explained based on the relationship among the ncele-ation rate, growth linear rate and undercooling ΔT.

Two methods for measuring small vibration displacement are reported. The sensitivity of small displacement of optical heterodyne amplitude narrow band de ection reaches 5.2×10-4 nm(2 kHz signal).The amplitude detection method is comparedwith the phase detection method by measuring noise spectrum.

A suggestion is proposed to treat the radiation transmission of free electron lasers in terms of waveguide laser theory. The investigation shows that there is a special low loss mode in the cavity. EH11 mode in for the dielectric waveguide,and the mode coupling loss is discussed.

Active mode-locking in semiconductor lasers has been obtained by means of opto-eleetronio feedback with pulses of 17.7 ps, pulse repetition rate of 926 MHz and peak power of 80mW.

Quantum statistics properties of multimode laser fields has been studied both theoretically and experimentally. The calculation shows that anticorrelation effect may appear in multimode laser fields. We have experimentally measured the noise power density and spectrum intensity fluctuation. The results agree with our theoretical calculations.

Above-threshold multiphoton ionization is investigated by means of essential states model. Analytical expression for the peak and total population of each continuum are presented, and the peak-switching effect is discussed.

Using a KNbO3 crystal of 6.9×5.3×3.3mm3 size tunable blue light at 485 -493nm was generated by frequency doubling of the tunable near IR output from an optical parametric amplifier. The energy conversion efficiency at 488.5nm has been measured to be 2.6%, and the peak power over 2kW.

Stable AlxGa1-xAs/GaAs CSP single modo visible LDs operating with fundamental transverse mode and single longitudinal mode are fabricated with liquid phase epitaxial method at 800C. The laser wavelength ranges from 779-820nm, and the main lasing performances are presented.

Two-photon resonant four-wave mixing together with CABS signals are observed in the four-wave mixing experiment in liquid picoline derivative. It leads to the complication of the CABS spectrum, whereas it has potential applications in the study of two-photon absorption process of organic molecules.

LN: Mg2+: Nd3+ single crystals were grown by Czochralski technique, their speetroscopioal parameters were calculated and analysed, and the infrared laser emission was observed with laser pumping.

The separating effect of D and E vectors of the fundamental frequency wave and the difference of 5 between the fundamental and the frequency-doubling waves are discussed. The calculated results of effective frequency-doubling coefficients of biaxial crystals belonging to five point groups are given in the principal optical axes cordinate system.