Optical parametric oscillator

摘要

An optical parametric oscillator includes a nonlinear element for converting an incident pump beam of angular frequency omegap into a combination of a signal wave of angular frequency omegas and an idler wave of angular frequency omegai at an arbitrary angular frequency ratio, a beam splitter for splitting the combination exiting the nonlinear element into the signal wave of angular frequency omegas and the idler wave of angular frequency omegai, a signal optical resonator for resonating the signal wave of angular frequency omegas at a resonator optical length Ls between an input mirror and an end mirror, and an idler optical resonator for resonating the idler wave of angular frequency omegai at a resonator optical length Li between an input mirror and an end mirror. The resonator optical length Ls of the signal optical resonator and the resonator optical length Li of the idler optical resonator are set to satisfy the relationship Li/Ls=omegai/omegas. A signal wave reflection side functioning as the end mirror of the signal optical resonator and an idler wave reflection side functioning as the end mirror of the idler optical resonator are faced in opposite directions to form a common end mirror. Continuous frequency tuning is conducted by moving the common end mirror within a range wherein a maximum variation range deltaL(Max) satisfies deltaL(Max)=2Cgamma/[omegas-omegapxLs/(Ls+Li)] (where C is the velocity of light and gamma is an optical resonator loss parameter).