Observation of Nondegenerate Two-Photon Gain in GaAs

摘要: Two-photon lasers require materials with large two-photon gain (2PG) coefficients and low linear nonlinear losses. Our previous demonstration of enhancement absorption in semiconductors for very different photon energies translates directly into 2PG. We experimentally demonstrate nondegenerate 2PG optically excited bulk GaAs via femtosecond pump-probe measurements. is isolated from other pump induced effects through the difference between measurements performed parallel perpendicular polarizations probe. An coefficient nearly 2 orders magnitude reported. The results point a possible way toward semiconductor lasers.