Correction of thermal blooming by optical phase conjugation

Abstract

We have observed accurate correction of laser-induced thermal blooming by optical phase conjugation. The thermal blooming produced up to a 36-fold increase in the far-field spot diameter and up to a 60-fold decrease in the far-field peak intensity. Stimulated Brillouin scattering was used as the phase-conjugate mirror with a reflectivity of 35% to 65%. A previously published theory regarding phase-conjugate correction of intensity-dependent aberrations suggested that nonunity reflectivity would adversely affect the phase conjugate's ability to compensate for thermal blooming. We found no evidence of this being the case.