Nonlinear Optical Effects: An Optical Power Limiter

Abstract

Parametric subharmonic oscillators and amplifiers at optical frequencies have recently been proposed, using optical maser pump sources together with the nonlinear optical properties of certain crystals. The simplest such structure would comprise a Fabry-Perot resonator filled with nonlinear crystal, the ends being transparent at the fundamental or pump frequency ω and reflecting at the subharmonic frequency ω/2. This paper demonstrates that such a structure will also function as an ideal optical power limiter at the fundamental. Power transmission through the structure at ω will limit sharply and flatly at the threshold level at which subharmonic oscillations commence; a large power-dependent reflection will also occur on the input end above threshold. The use of such a limiter for eliminating spiking in optical masers, and for other purposes, is suggested.