Generation of Two Self-Pumped Phase-Conjugated Waves at Different Wavelengths Using a Single Photorefractive Crystal

The generation of two self-pumped phase-conjugated waves at different wavelengths using a single undoped barium titanate crystal is presented. One signal beam (514.5 nm) is directed at the (-100) face of the crystal, while the other (488.0 nm) is incident on the opposite (100) face, producing two phase-conjugated images at beam power ratios of up to 1:25 with an incidence offset of 2 mm. The dynamic range over which phase-conjugated images are obtained is thus greater than in the case of a single wavelength, due primarily to the absence of interference between the two signal beams at different wavelengths.