Abstract

Thin-film polarizers are essential for efficient frequency conversion of high-energy lasers used for inertial fusion energy experiments. Many polarizer designs appear in the literature. Designs for single-wavelength devices are best compared by examining both the contrast ratio (T_p/T_s) and the throughput (T_p) as a function of the angle of incidence. A design using tantalum pentoxide/silicon dioxide is optimized for use at 1054 nm. These materials can be accurately controlled during deposition and have favorable damage characteristics. A method is described for accurate calibration of a physical thickness monitor in a planetary deposition system. A reflectometer modified to automatically measure the angular spectrum of contrast and throughput is essential for fine-tuning the design. Contrast ratios exceeding 1000:1 with throughput greater than 0.96 are realized on polarizers as large as 35 cm. The results for polarizers up to 60 cm (30 cm clear aperture) are presented. Performance of the polarizers on the 24-beam OMEGA laser is summarized.

© 1990 Optical Society of America