Self-interaction of incoherent light beams

Valerii S. Butylkin, Yury G. Khronopulo, A. E. Kaplan +1 more

Padma Kant Shukla, Lennart STENFLO

Mordechai Segev, Amnon Yariv

Phase-conjugate backscattering in photorefractive (PR) materials, which can be considered a special case of two-beam coupling, involves interaction between two counterpropagating beams via light-induced reflection gratings. Since this backscattering results from interference between the beams, it requires mutual temporal coherence. Moreover, when one beam is self-generated, the input beam is required to have a long coherence length.

Alexander A. Betin, Guerman A. Pasmanik

Jiasen Zhang, Shin Yoshikado, Tadashi Aruga

We demonstrate the bistable behavior in a photorefractive self-pumped phase-conjugator (SPPC) theoretically and experimentally. In the method, an incoherent erase beam is used to erase the four-wave mixing (FWM) region of the SPPC, and thus the threshold of the SPPC depends on the intensity ratio of the erase beam to the sum of the coherent beams in the FWM region. Even a white light can be used to control the reflectivity as a switch.

Philippe Lalanne