Abstract

The operation of the double phase conjugate mirror (DPCM) has in the past been described theoretically^[1] through the use of one-dimensional scalar coupled wave theory.^[2] Calculations of measureable quantities, such as phase conjugate reflectivity, based on this approach have yielded results which agree quite well with experiments.^[3] This 1-d scalar theory predicts that the DPCM works as an oscillator, with the phase conjugate beams building up from zero at the crystal boundaries (as a function of the longitudinal spatial coordinate) when the coupling strength is above some threshold value. In the laboratory, the DPCM does indeed appear to have this property, since its operation is observed to depend critically on the angles of the pump beams inside the crystal with respect to each other and to the crystal’s optic axis, parameters upon which the coupling strength depends. The phase conjugate beams appear to “turn on” suddenly to full intensity as the orientation of the pump beams within the crystal is changed slightly.

© 1992 IQEC