High-reflectivity, wide-bandwidth optical phase conjugation via four-wave mixing in potassium vapor

Abstract

We report on a high-reflectivity (up to 670%) wide-bandwidth (up to 230 MHz) phase-conjugate mirror formed using backward-four-wave mixing with continuous-wave pump beams in a 2-mm potassium vapor cell. The reflectivities and bandwidths are significantly larger than have been measured previously, and the bandwidth is ten times greater than is predicted theoretically. The reflectivity-bandwidth product is more than an order of magnitude improvement over those previously achieved with other continuous-wave phase-conjugate systems.