Red and Blue Light Generation in an LiTaO₃ Crystalwith a Double Grating Domain Structure

Simultaneous red and blue light generation in an LiTaO₃ crystal with a double grating structure is first reported. The double grating consists of two separate domain reversal sequences (superlattices) in series and is fabricated by field poling technique at room temperature. Using a picosecond 532 nm laser as a pump source, the red light at 631 nm and blue light at 460 nm are generated at the same time. A possible application of the superlattice crystal is presented.