Optical phase conjugation of the two-photon-pumped frequency upconversion backward stimulated emission of a new dye solution has been demonstrated. When the 1064-nm pump intensity reaches a certain threshold value, a highly directional and phase-conjugate backward stimulated emission at ~616-nm wavelength can be observed. After backward passage through an aberration plate placed in the input pump beam path, the introduced aberration influence (1.6–1.8 mrad) can be entirely compensated by backward stimulated emission with a final beam divergence of only 0.23 mrad. The net conversion efficiency from the absorbed IR pump energy to the backward visible stimulated emission energy can reach 10%.
© 1997 Optical Society of America
Guang S. He, Yiping Cui, Makoto Yoshida, and Paras N. Prasad, "Phase-conjugate backward stimulated emission from a two-photon-pumped lasing medium," Opt. Lett. 22, 10-12 (1997)