Abstract

We propose and demonstrate a technique for suppressing the optical noise of the photorefractive amplifiers that exhibit a sharp gain resonance around an optimum pump-to-signal angle. The amplification of extremely weak images is achieved when the entrance face of the crystal is tilted with respect to the pump beam direction. In Bi₁₂SiO₂₀ subpicowatt optical signals are detected with this technique.

© 1991 Optical Society of America

High-fidelity image amplification and phase conjugation in photorefractive Bi₁₂SiO₂₀ crystals

N. A. Vainos and M. C. Gower
Opt. Lett. 16(6) 363-365 (1991)

Amplification of optical signals in Bi₁₂TiO₂₀ crystal by photorefractive surface waves

A. V. Khomenko, A. García-Weidner, and A. A. Kamshilin
Opt. Lett. 21(14) 1014-1016 (1996)

Amplified phase-conjugate beam reflection by four-wave mixing with photorefractive Bi₁₂SiO₂₀ crystals

H. Rajbenbach, J. P. Huignard, and Ph. Refrégier
Opt. Lett. 9(12) 558-560 (1984)

Readout properties of the specklegram recorded in photorefractive Bi₁₂SiO₂₀ crystal

Kiyoshi Nakagawa and Takumi Minemoto
Appl. Opt. 30(17) 2386-2392 (1991)

Two-wave mixing in photorefractive Bi₁₂SiO₂₀ fibers

Alexei A. Kamshilin, Raimo Silvennoinen, Timo Jaaskelainen, Claudio J. Lima, Marcello R. B. Andreeta, and Victor V. Prokofiev
Opt. Lett. 18(9) 690-692 (1993)