Abstract

Population grating, phase conjugation by degenerate four wave mixing PCD4WM and optical bistability have been studied in Cr⁺³ doped crystals^(1,2). In these materials the nonlinearity originates from the population of dopant ion metastable state, which has a complex suscetibility different from that of ground state⁽¹⁾. In our PCD4WM measurements in Ruby and GdAlO₃:Cr⁺³ we observed that self-focusing and transverse effects determinate the saturation behaviour of the conjugation efficiency⁽²⁾. In this work we measured and calculated the diffraction rings pattern from a GdAlO₃:Cr⁺³ crystal. These rings were observed earlier in thin liquid-crystal film and can be explained by the spatial transverse self-phase modulation of the laser beam transmitted by the nonlinear media⁽³⁾.

© 1988 Optical Society of America