Fresnel Coefficients for a Phase Conjugator

摘要

Optical phase conjugation via four-wave mixing is examined in detail. The Fresnel coefficients for reflection and transmission of a plane wave irradiating the surface of the phase conjugator are calculated. It appears that for normal incidence and a weak nonlinear interaction the device produces the phase-conjugated beam with respect to the incoming beam. For finite angles of incidence or stronger nonlinearities in the crystal, the generated wave deviates from the ideal conjugated wave, and also a second reflected wave appears. It is pointed out how this could explain certain controversies regarding atomic lifetimes near the surface of a phase conjugator. Keywords: Nonlinear optics, Fresnel coefficients, Phase conjugator, Four wave mixing, Atomic lifetimes, Theory. (MJM)