Theoretical analysis of self-phase locking in a type II phase-matched optical parametric oscillator

摘要

We analyze a doubly-resonant type II phase-matched optical parametric oscillator that includes an intracavity waveplate for inducing mutual injection locking between the signal and the idler. The intracavity waveplate provides a linear coupling between the normally orthogonally polarized signal and idler fields and allows for mode locking at frequency degeneracy. Under mode locked conditions the signal-idler phase difference is locked and the optical parametric oscillator becomes self-phase locked. The signal-idler phase can be adjusted by changing the operating point within the locking range. Two self-phase locked modes with different thresholds and signal-idler phases are possible. Characteristics of the self-phase locked regime are presented for different linear coupling strengths.