The methods of eliminating self- mode- locking and realizing single longitudinal mode operation in silicate glass laser is reported. The experimental results have been given.

Deposition rate distribution of optical coating deposited by ion beam sputtering were calculated using Ganssian distribution of ion beam intersity. The results show that the deposition rate distribution deviates from that of the cosine distribution, the position of peak value depends on the incident angle and Gaussian radius of ion beam. The experimental results agree with the theoretical results perfectly.

Westbrook's theory has been adopted to analyse.the effects of a grating monochramator on the measurement of modal reflectivity at AR coated facets of a semiconductor laser diode. It has been verified that the measured modulation index and reflectivity changes with the exit slit width periodically. The period has been identified to correspond to the diode mode spacing. The analysis has also predicted that when the passband width of the monochramator is somewhat larger than the diode mode spacing, the measured peaks and valleys will be different from their real positions by a half of the mode spacing.

The paper proposes a method for measuring the triplet lifetime of laser dyes by ESR technique with an error of about 15%.

The asymptotic theory of diffraction gratings in the scalar domain is used to design the soft X-ray laser reflective output multilayer mirror, whose diffractive characters are analysed. The factors affecting the output efficiency are also analysed and discussed.

The principle and configuration of calorimeter are described for the measurement of frequency-doubled laser light. The operating parameters given herein satisfy the energy requirements for shorter wavelength, shoter pulse duration laser light at the Shengguang Facility, and the overall energy uncertainty is 5%.

With finite- element method, numerical calculations of instantaneous temperature distribution in layered magneto-optical (MO) films are given. In the analysis, the emphasis is put on the ambient temperature dependence of temperature profile in layered structure, and the pulse duration dependence of minimun writing power is found at various ambient temperatures. The analysis presents an useful means to further study the characteristics of thermomagnetic recording and magneto-optical readout of MO disks used at different ambient temperatures.

Production and development of the plasma shock wave during the ophthalmic operation have been studied by exploring an eye model simulating the laser operation. According to the experimental results, physical mechanism hypothesis of action upon the curing eye tissues of the plasma shock wave and possible influence on the surrounding tissues during the operation have been put forward. The hypothesis may explain satisfactorily some phenomena and has been verified during the clinical applications.

The detection of pollutant components in air of Hong Kong by photoacoustic spectroscopy is described. The detection reults show that some toxic components exhausted by automobiles:formaldehyde, acetaldehyde, acrolein, ethylene, propene and cycloheptatrine etc. are the major pollutant components of street air there.

A theoretical model for amplifier of pulsed chemical oxygen-iodine laser is presented. The calculation shows that an oxygen-iodine amplifier using multiple optical path may get high amplification ratio and high chemical efficiency.

We constructed experimentally the four-stage dye amplifier pumped by a Q-switched frequence-doubled Nd:YAG laser with repetition rate of 10 Hz. It amplified 43 fs optical pulses to energy of 100μJ and pulsewidth of 125 fs. Optical pulses with pulsewidth of 70 fs and peak power of 1 GW has been generated using a four- prism sequence compressor.

We analyzed the harmonic property of the two-dimensional undulator FEL by using Madey' s theorem. We have derived the formulas of harmonic spontaneous emission power density, small signal gain of this undulator FEL and the coupling coefficients between the electrons and the radiation field. From the numerical calculation results we came to the conclusions that by utilizing the two-dimensional undulator, we can enhance the coupling between the electrons and the radiation field, and hence increase the harmonic spontaneous emission power density and gain. Furthermore, under certain conditions we can not only obtain odd but also even harmonic radiations on the axis.

The gain characteristics of a pulsed oxygen-iodine chemical laser has been studied theoretically. The necessary iodine atom is initiated by electrolytic dissociation of CH3I from low energy electrons. The influences of pressure, composition and the dissociation degree of CH3I on gain are investigated in detail.

The fluctation of photon number of a two-photon laser by coherent pumping with two-photon losses is calculated using Langevinian method and quasilinearization procedure. The result shows that there is no seqeezing in photon number when the laser operates at the vicinity of the threshold.

We report a new kind of biomolecular LB films composed of a photosensitive protein-bacteriorhodopsin. The saturated absorption intensity and nonlinear refractive index of the material are estimated to be 0. 42 W/cm2and 5×10-22cm2/W and the typical response time of the nonlinearities is about 1ms. High to third-order self-diffractions by population gratings in the LB films have been observed in the degenerate two- beam interaction experiment. The relation between intensity of each order diffracted beam upon the total incident intensity is deduced based on a simplified photocircle model of bacteriorhodopsin. The saturated absorption intensity and nonlinear refractive index of the material are then calculated by fitting the experimental data with the theoritical formuls.

The paper reports some new results on the generation of infrared stimulated radiation based on dipole-dipole or dipole-quadrupole hybrid excitation of Na2-Na system and collision energy-transfer.

The first home-made YAG-KTP extracavity frequency doubl lasering pumped by LD was developed. The measured pump threshold, green light output power and doubling efficiency are 31.8mW, 0. 2 mW and 2% , respectively. The experimental setup and results are discussed.

Two-photon absorption phenomenon of Ho3+ ion in HoP5O14 noncrystalline induced by 1.06 μm of Nd:YAG pulsed laser is reported. We fond it is a direct, not step by step, two-photon process storting from 5I8 state and can be ascribed to the third order perturbation resulted from spin-orbit interaction.

Optical and thermal properties of heavy hydrocarbon surface is studied by laser photothermal displacement spectroscopy for the first time. The effects of experimental parameters on the photothermal displacement signal are considered in detail. A new method for measuring the thermal diffusivity, the characteristic parameters of focused laser beam and the focal length of the focusing lens is introduced. The result is in agreement with the theoretical calculation.