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Diamond-like films have been deposited by dc plasma chemical vapor deposition (CVD). During deposition, the characteristics of the plasma have been measured by means of the Langmuir single probe. The structure of the deposits has been studied by x-ray diffraction, Raman spectroscopy and Fourier transform infrared spectroscopy.

We observe the phenomenon of priority oscillation of the unexpected σ-polarization in high-power Nd:YVO4 ring laser. The severe thermal lens of the σ-polarized lasing, compared with the π-polarized lasing, is the only reason for the phenomenon. By designing a wedge Nd:YVO4 crystal as the gain medium, the unexpected σ-polarization is completely suppressed in the entire range of pump powers, and the polarization stability of the expected π-polarized output is enhanced. With the output power increasing from threshold to the maximum power, no σ-polarization lasing is observed. As a result, 25.3 W of stable single-frequency laser output at 532 nm is experimentally demonstrated.

Small-angle X-ray diffraction study of amorphous a-Si:H/(a-SiNx:H) periodical multilayer thin films and some single layer films has been undertaken. A number of satellite peaks were found in the lower side of Bragg diffraction peaks of multilayer thin films with a less number of periods. A number of diffraction peaks were also found for the small-angle diffraction of single layer films. We have presented a simple formula for calculating the X-ray diffraction intensity of multilayer and single layer films. A satisfactory explaination of experimental results was obtained. Consequently, a simple method for measuring the total thickness of both multilayer and single layer thin films has been presented.

The thermal expansion coefficients (along and normal to the chain direction) of PTS have been measured by differential parallel-plate capacitances from 77 K to 273 K. A sudden change near the phase transition temperature 195 K and a negative expansion coefficient near 200 K along the chain direction have been observed. The causes of these result are discussed qualitati-vly.