In this paper it is proved that the bulk stress of electromagnetic field equals the Bohm force of electromagnetic field. This indicates that there is more profound physical meaning of the gradient vector potential of electromagnetic field.

Influence of thermal deformation in mirrors upon the resonator parameters is discussed. In designing a high power laser and a folded-resonator CO2 laser in particular, it must be considered in advance as much as possible.

Using ray transfer matrix, we have computed beam radii and mode volumes in the folded resonutor and the dependence on mirror curvature of resonator and the parameter a of the gas plasma negative lens. Results indicate that folded resonator configuration used in a laser with longer plasma length, not only reduces space length of the device, but also possesses significance for obtaining stable high power output taking into account of the effect of negative plasma lens.

This paper describes the theoretical analysis and experimental investigation of PTM mode operation of the flash-lamp pumped R-6G dye laser. A discussion of influence on the efficiency of PTM mode operation has been given. As compared to the normal operation, the peak power output has been increased by 22 times with an output pulse-width of 5~25 ns.

With copper vapor or copper halide vapor as laser medium, excited by high repetition frequency resonance Blumlein discharge circuit, lassr outputs are obtained at 510.6 nm and 578.2 nm. For charge capacitance of 1.5nf, charge voltage of 6000V and a repetition rate of 10kHz, the average output laser power is 1.2 W.

An optical arrangement was designed using stimulated Raman scattering (SRS) as the coherent light source and many kinds of frequency mixing between the pumping laser beam and diiferent orders of Stokes and anti-Stokes lines were obtained. The resonance phenomenon of coherent anti-Stokos Raman scattering in benzene has been observed and very intense second-order CARS has been obtained.

Thermal lens effect was calculated for several rod-axis orientations. Due to the thermal strain photoelastic effect., there is a change of refractive indices in the [001] and the [211] rods. The change depends on the angles between the main axis of refractive index and the coordinate system. The thermally induced bi focus in these two directions is different from that of [111] rods. The former is a function of the angles, whereas the latter is not dependent on the angles. Relation between effective thermal focal length and input power measured experimentally are in good agreement with theory.

The relief patterns of photoresist grating in GaAs (100) plane substrate is produced by holographic interferometric exposure and photoresist development. The grating relief patterns of photoresist is then transfered to GaAs (100) plane substrate by preferential chemical etching. Gratings with a period of 0.33m have been successfully fabricated on GaAs (100) plane substrate and the grating corrugation has better V-shaped groove profile.

In this paper some charaetristics caused by bleaching processing for holographic emulsion are considered and the method for preparing the phase filter is given.

Optical absorption of Ge with different resistivity has been measured using photo-acoustic speotroscopic method and some problems of this technique have been investigated. Experimental data of optical absorption of Ge and photo-acoustic spoctroseopy have been obtained.

A scanning interferometer for Ar+ lasers has been developed, some frequency domain characteristics of actively mode-locked Ar+ lasers were observed by using this scanning interferometer, frequency spectrum of longitudinal mode of Ar+ lasers in mode-locked state was photographed. Resolution of 30 MHz for the scanning interferometer was measured experimentally with a finesse of 150.

This paper reports a new type of unbleached phase silver medium hologram on silver halide emulsion and its applications in character and image storage, such as high density data holographic recording, duplicating, reconstruction and printing of documents. A hologram of 1 mm diameter can record 1~2 pages of magziae in sextodecimo. The reconstructed images are clear without speckle noise, quality of the duplicated holograms is comparable to that of the original and has permanent lifetime. The 1st order diffraction efficiency of this new unbleached phase silver medium grating is about 20%.

A brief account is given on the 11th IQEC, putting emphases on the latest achievements on laser speetroscopy, nonlinear optics and advanced laser devices.