Four-wave mixing and edge-enhanced optical correlation in a Ce : KNSBN crystal

In the case of degenerate four-wave mixing in a cerium-doped potassium sodi um strontium barium niobate (Ce:KNSBN) crystal, it is found that the transm ission grating is dominant when the incident beams are extraordinarily pola rized, the crystal response is more rapid, and the conjugate beam is more i ntense. Furthermore, the variation of the conjugate beam intensity forms a loop as the fringe modulation of the transmission grating varies. Based on this observation, we have implemented edge enhancement of an image and edge -enhanced optical correlation via four-wave mixing in a Ce:KNSBN crystal wi thout the requirement of reversal of the signal-pump-beam intensity ratio. (C) 2000 Optical Society of America OCIS codes: 100.2980, 100.4550, 160.532 0, 190.5330.