OPTICAL IMPLEMENTATION OF A MULTIWAVELENGTH HALF-ADDER

We report optical implementations of multiwavelength digital logic operations, demonstrating a half-adder that utilizes photoinduced gratings in photorefractive media. Phase-matched diffraction from multigratings is employed to achieve spectrally parallel arithmetic operations of CARRY, whereas multiwavelength holographic interference is employed to achieve spectrally parallel arithmetic operations of SUM. We also propose the use of phase-matched cross-polarization readout in uniaxial photorefractive crystals to achieve collinear operation. We show that a parallelism of hundreds of bits is possible.