Photorefractive properties and alternating electric field gain enhancement of vanadium-doped cadmium telluride and related compounds

Abstract

Recent studies of the photorefractive response of CdTe have demonstrated it to be a highly sensitive material with a broad near infrared sensitivity extending to beyond 1.5 μm[1,2]. Desirable parameters, such as large electrooptic coefficient, small dielectric constant, large carrier mobility and availability in semi-insulating form, makes CdTe a potential material of choice for many applications[3]. This study focuses on photorefractive characterization of Bridgeman grown crystals with the goal of providing the information that can lead to the optimization of key photorefractive parameters. We have observed gain and broad sensitivity (1-1.5 μm) in vanadium doped CdTe and Cd0.96Zn0.4Te samples. Mixed alloys such as CdZnTe and CdMnTe allow band gap engineering such that the sensitivity range could be tuned toward the visible and be matched to the wavelength of interest. An applied alternating (AC) field gain enhancement technique is used to demonstrate net gain which is a prerequisite for coherent amplification and self-pumped phase conjugation.