QUADRUPLE GRATING PERIOD PPLN OPTICAL PARAMETRIC OSCILLATOR DIFFERENCE FREQUENCY GENERATOR WITH COMMON DOUBLY RESONANT CAVITY

摘要

The present invention relates generally to the field of optical devices and particularly to embodiments of a four-stage PPLN optical parametric oscillator/difference-frequency generator configuration. The present invention allows simultaneously and colinear generation of four wavelengths in efficient use of the pump signal. A first embodiment comprises a singly resonant cavity (38) having an internal monolithic non-linear optical medium (20) disposed in the cavity. The cavity is bounded by an input mirror (34) and an output mirror (36). The monolithic non-linear optical medium is divided into four regions each having its own grating period. A second embodiment of the present invention comprises a monolithic non-linear optical medium (40) divided into four separate regions (46, 48, 50, 52). The entrance facet (42) and exit facet (44) of the monolithic non-linear optical medium includes a coating (58, 60) which acts as the cavity mirrors.