摘要
We have derived a coupled-wave theory for optical parametric amplification and oscillation in a dielectric-modulated nonlinear optical material whose dielectric period is in resonance with the signal wave. The theory is fully consistent with the Manley–Rowe relation for nonlinear frequency conversion. A distributed-feedback optical parametric oscillator, while it retains most of the mode characteristics of a distributed-feedback laser, has the additional advantage of wavelength selectivity. Unlike a distributed-feedback laser amplifier, a distributed-feedback optical parametric amplifier, when it is seeded with an idler wave, does not have the problem of seed-signal feedback. The idler wave, which does not exist in an ordinary distributed-feedback laser, has a profound influence on the mode thresholds and resonance frequencies of a distributed-feedback optical parametric oscillator.