Sum frequency generating devices are disclosed. The devices include a waveguide having a multilayer structure comprising at least one nonlinear semiconductor material. In a preferred embodiment, each of the layers of the multilayer structure has the same thickness and alternate layers have a first and...http://www.google.com/patents/US5051617?utm_source=gb-gplus-sharePatent US5051617 - Multilayer semiconductor waveguide device for sum frequency generation from contra-propagating beams
