The process of phase conjugation by self- pumped four-wave mixing using Brillouin scattering has been described previously.1 In this system, an input pump beam provides gain through the nonlinear action of a Brillouin medium. Optical radiation builds up in a cavity surrounding the Brillouin medium, forming two counterpropagating beams. These in turn interact with the input pump beam to generate a fourth beam through four-wave mixing mediated by the Brillouin medium. Since one cavity beam is the phase conjugate of the other, the output radiation is the phase conjugate of the input pump beam. It is also shifted in frequency by twice the Brillouin shift relative to the pump. We report on the construction of both linear and ring oscillators, the fidelity of the phase conjugation, the demonstration of unidirection oscillation in a ring resonator, the presence of Raman scattered radiation in the optical cavity, and the presence of more than one mode in a linear resonator.
© 1989 Optical Society of AmericaPDF Article