Four-wave mixing in bulk GaAs microcavities at room temperature

We studied pico- and femtosecond degenerate four-wave mixing in bulk GaAs Fabry-Perot microcavities at room temperature. For wavelengths below the GaAs band edge, a cavity with a finesse of approximately 20 yields an enhancement of the diffracted signal by more than two orders of magnitude as compared to a cavityless GaAs layer of the same thickness (685 nm). The cavity-enhanced nonlinearity of the interband transition results in a diffraction efficiency eta approximate to 0.5% for 150 pJ pulses with a duration of 900 fs at 878 nm, being 400 times larger than that for the bare GaAs reference sample. (C) 1996 American Institute of Physics.