Amplification of high bandwidth signals through two-wave mixing in photorefractive Bi12SiO20 crystals

Abstract

We report a new nearly degenerate two‐wave mixing interaction in photorefractive Bi₁₂SiO₂₀ crystals in which the signal beam is time modulated at high frequency. The beam coupling phenomena and the time integration properties of the crystal allow us to achieve a differential gain γ_diff on the transmitted signal beam. The dependence of γ_diff versus the duty cycle of the modulated signal is analyzed. Amplification and regeneration of periodic, or random sequences of information bits are experimentally demonstrated.