High-reflectivity four-wave mixing by saturable gain in Rhodamine 6G dye

Four-wave mixing in a saturated gain medium has been modeled numerically, and the predictions for the reflectivity have been compared with experiments carried out in the laser-pumped dye Rhodamine 6G. It is demonstrated that the saturable absorption of the inversion laser pump has a dramatic influence on the intensity dependence of the four-wave-mixing reflectivity.