Method and apparatus are provided for NLO switching by first providing a phase-matched SHG grating which outputs a reinforced SHG beam only when two input beams of frequency (.omega.) are present in two modes of such wg. The so encoded NLO switch is operated by directing at least two input pulsed laser...http://www.google.ca/patents/US5557699?utm_source=gb-gplus-sharePatent US5557699 - Nlo waveguide "and" switch and method therefor
