Abstract

Hologram recording was performed in Se_1-x/Ge_x films for different compositions, where x = 0, 3, 5, 8, and 12-wt. % Ge. These films 3400 Å thick were deposited on glass substrates by thermal evaporation from a tantalum crucible. The expo sure characteristics such as diffraction efficiency were determined for different exposure power. It was found that selenium films alloyed with germanium showed significant improvement in their exposure characteristics. The best result for the diffraction efficiency was obtained for Se₉₇Ge3 composition. A maximum efficiency of 3.2 % was obtained for an exposure power 910 mW cm^-2, beam ratio k = 1.07, and spatial frequency of 220 lines mm^-1. However, increasing the exposure power and the concentration of germanium only leads to a decrease in the diffraction efficiency. Optical constants were calculated from the transmittance and reflectance data.

© 1986 Optical Society of America