Double Phase Conjugated Mirror and Double Colour Pumped Oscillator using Band-edge Photorefractivity in InP:Fe

The Double Phase Conjugated Mirror (DPCM) and the Double Colour Pumped oscillator (DCPO) are particularly interesting devices for reconfigurable optical interconnects. In a DPCM two mutually incoherent pump beams (at nearly identical wavelengths) incident on the opposite faces of a photorefractive (PR) crystal share a common grating which diffracts them into the phase conjugated of the opposite one. When the wavelength difference of the interacting beams is important (larger than the grating selectivity), they can still induce a common grating (DCPO). Recently DPCM has been observed in Indium phosphides:Fe(6) and Gallium arsenides:EL2(7) at 1.06 microns and DCPO has been achieved in InP:Fe using 1.06 and 1.32 um wavelengths. This paper presents new results on both DPCM and DCPO obtained in InP:Fe at wavelengths close to its band edge. More precisely, we have observed DPCM at wavelength down to 970 nm and DCPO between a fixed wavelength of 1.047 microns and a variable one down to 965 nm. Using a wavelength close to the band edge has two major implications for PR devices. There is indeed an increase of the optical absorption a, but the effective electro-optic coefficient is greatly enhanced through the Franz-Keldysh affect which has already been exploited to achieve large 2WM gains in GaAs. This article is from 'Organization of the Optical Society of America Photonic Science Topical Meeting Series. Volume 14. Photorefractive Materials, Effects, and Devices Held in Beverly, Massachusetts on 29-31 July 1991,' AD-A253 001, p310-313.