Transverse-mode structure of a phase-conjugate oscillator based on Brillouin-enhanced four-wave mixing

A phase-conjugate oscillator consisting of a phase-conjugate mirror and a conventional mirror is discussed. The phase-conjugate mirror is based on a Brillouin-enhanced four-wave mixing process and produces a conjugate wave with no frequency shift and with a reflectivity greater than 100%. The beam divergence and near-field spot size of this oscillator have been measured for various cavity lengths and conventional mirror radii of curvature. A theoretical analysis of the mode structure of this oscillator has been performed assuming a Gaussian reflectivity profile for the phase-conjugate mirror. The measurements are in good agreement with the predictions of this model.<
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