Fast optical addressing using plasma gratings stabilized by deep centers in semiconductors

Abstract

We study the subnanosecond optical addressing capabilities of semiconductors based on the diffraction properties of plasma index gratings. We use degenerate four-wave mixing experiments at 1.06 micrometers . The diffraction efficiency of the refractive index grating remains constant ((eta) equals 5 X 10 -4 ) in the nanosecond time scale. The grating erasure is possible however using a uniform picosecond illumination: an 80% decrease of the diffraction efficiency is achieved with only 25% of the writing energy. We show that the best model to explain our experimental results is based on the plasma density modulation stabilized by charged deep centers via the electrostatic screening effect.