Spatial modulation of the dielectric function using free carriers and or coherent effects in quantum-well semiconductor microcavity

Results on picosecond degenerate four-wave mixing in semiconductor microcav ity are presented. The device is made of GaInAs/GaInAsP multiple quantum we lls enclosed in an asymmetric Fabry-Perot microcavity 80%-98%. For incident photon energies below the excitonic energy, the spatial modulation of the dielectric function can be generated by free carriers and/or coherent effec ts. We show that the last one can be significant; an input diffraction effi ciency of 2% with only 1 mu J/cm(2) pump fluence is achieved. This result d emonstrates a new way to obtain ultrafast, sensitive, and low-dissipative d evices. (C) 1999 American Institute of Physics. [S0003-6951(99)03420-8].