We theoretically studied the retracing behaviors of the phase-matching angle in b-BaB2O4 optical parametric oscillators with noncollinear phase matching when they were pumped with the harmonic of a Nd:YAG laser. The results imply that two or more sets of signal–idler outputs can be observed at certain phase-matching angles. Meanwhile, we observed that over a quite broad signal wavelength range ...

Under extended phase-matching conditions, the first frequency-derivative of the phase-matching function is zero and the phase-matching bandwidth is greatly increased. We made extensive three-wave mixing measurements to identify the operating point for extended phase matching, thus permitting us to observe a type-II phase-matching bandwidth of 100 nm centered at the fundamental wavelength of 158...

We present a brief overview of different methods for simultaneous phase-matching of several parametric optical processes (the so-called multistep cascading) in engineered structures with the modulated second-order nonlinear susceptibility. In particular, we discuss the possibility of double phase-matching in both uniform and non-uniform quasi-phase-matched (QPM) periodic optical superlattices a...

Phase matching is a critical requirement for coherent nonlinear optical processes such as frequency conversion and parametric amplification. Phase mismatch prevents microscopic nonlinear sources from combining constructively, resulting in destructive interference and thus very low efficiency. We report the experimental demonstration of phase mismatch-free nonlinear generation in a zero-index op...

For optimal Chi((2)) nonlinear interaction the phase matching condition must be satisfied. For type I and type II phase matched materials, this is generally achieved by controlling the temperature of the nonlinear media. We describe a technique to readout the phase-matching condition interferometrically, and experimentally demonstrate feedback control in a degenerate optical parametric amplifie...