Recent experimental results have shown that the highly directional frequency-upconverted backward-stimulated emission from a two-photon-pumped lasing medium possesses the property of optical phase conjugation. To explain this property, a Gabor’s quasi-collinear holographic model is proposed for a two-photon-pumped gain medium. According to this model, the input IR pump beam (after passing through a phase-distorting medium or an aberration plate) can be assumed to consist of two parts: an undisturbed regular portion and a phase-distorted irregular portion. These two portions interfere with each other and create a volume holographic grating within the pumped region inside the gain medium. While an initial regular backward-stimulated emission (as a reading beam) is passing through this holographic grating, a diffracted wave is created and amplified together with the reading beam. A rigorous mathematical analysis shows that under certain conditions the combination of these two parts (the reading beam plus the diffracted wave) of the backward-stimulated emission can be an approximate phase-conjugate field of the total input-pump field.
© 1998 Optical Society of AmericaFull Article | PDF Article
Claire Gu and Pochi Yeh
J. Opt. Soc. Am. B 8(7) 1428-1432 (1991)
E. Le Bihan, M. Pinard, and G. Grynberg
Opt. Lett. 11(3) 159-161 (1986)
A. A. Zozulya
Opt. Lett. 16(8) 545-547 (1991)