Modified GaSe crystals for mid-IR applications

We have synthesized stoichiometric batches of GaSe by reacting mixtures of the parent components and have grown centimeter-size modified single crystals of GaSe by the vertical Bridgman technique. GaSe crystals doped with silver, indium and silver gallium selenide were fabricated for wavelength conversion. Silver doping produced scattering centers which could be dissolved by annealing at temperatures above 700 degrees C. Crystals cracked extensively during the annealing process and optical quality deteriorated. SHG measurements of In-doped crystals showed a "d" value of 49 pm/V for low concentration In-doped GaSe crystals. The silver gallium selenide doped GaSe crystals showed a "d" value of 75 pm/V which resulted in significant increase in the "d(2)/n(3)". (C) 1999 Published by Elsevier Science B.V. All rights reserved.