Abstract

Spatially selective ionization of defect sites known as “DX” centers produces phase-type holographic diffraction gratings which have been reported with efficiencies above 10% for grating periods as small as 135nm [1,2]. Diffraction gratings in Te-doped AlGaAs are persistent for years for sample temperatures below an annealing temperature which is about 70K. The mechanism for grating decay (recapture of electrons into DX centers) is thermally activated with a barrier height of 0.24eV for this material and therefore its rate is a strong function of temperature. We have shown [3] that when operated above the annealing temperature, these DX materials can support dynamic four-wave mixing and optical phase conjugation (PC) using milliwatt infrared beams [4].

© 1996 Optical Society of America