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 phosphidesFe6 and Gallium arsenidesEL27 at 1.06 microns and DCPO has been achieved in InPFe using 1.06 and 1.32 um wavelengths. This paper presents new results on both DPCM and DCPO obtained in InPFe 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.