Effects of signal detuning on phase conjugation

Abstract

The formulations of degenerate three-wave and four-wave phase conjugation are generalized to include signalpump detuning. The theory is an extension of grating-dip spectroscopy. The reflection bandpass is shown to be limited by the power-broadened bandwidth (proportional variant 1/T(1)) of the two-level population difference. Unlike for runningwave saturation, the signal-absorption coefficient saturated by a standing wave shows virtually no gain regions.