We derive a coupled-wave theory for backward phase-matched optical parametric amplifiers and oscillators in a dielectric modulated nonlinear optical material. Unlike a forward phase-matched distributed-feedback optical parametric oscillator, a backward oscillator of this type can have high-threshold gap modes at Bragg resonance and low-threshold detuned modes. In addition to the structure feedback loop, the internal feedback loop in the counterpropagating waves strongly influences the resonant-mode formation in this oscillator. A backward distributed-feedback optical parametric oscillator also exhibits the mode-dependent oscillation threshold similar to that for a distributed-feedback laser and yet has the additional advantage of wavelength selectivity in a much broader parametric bandwidth.
© 2005 Optical Society of America
Yen-Chieh Huang, "Theory of backward distributed-feedback optical parametric amplifiers and oscillators," J. Opt. Soc. Am. B 22, 1244-1254 (2005)