Abstract

Recently, there has been increased interest in the use of resonant atomic systems for performing optical-wavefront conjugation. This interest has arisen because resonant systems are inherently fast, with response times in the nanosecond range. However, resonant systems tend to have lower efficiencies and greater optical power requirements than do photorefractive crystals, such as BaTiO₃. In this paper, we explore the possibility of using a highly efficient Raman laser¹ in a sodium-vapor cell to obtain efficient phase conjugation at greatly reduced optical power densities. In this demonstration we use a self-pumped (linear-cavity) conjugator for simplicity. With this setup, we have achieved phase- conjugate reflectivities of 2% with input powers of only 20 W/cm². This is only 2% of the optical power density previously reported² to obtain comparable reflectivity with a self-pumped scheme in sodium vapor.

© 1991 Optical Society of America