Transversely pumped nonlinear conversion structure which generates counterpropagating guided waves: Theory and numerical modeling

A transversely pumped, nonlinear conversion structure which generates counterpropagating, guided signal and idler beams is examined. Existing scalar theory is extended to include the vector nature of the electromagnetic fields. Based on these results, a detailed simulation of proposed GaAs-AlGaAs structures is described. The results of the simulations highlight pitfalls not obvious in the original work, The simulations indicate, however, that proper design of the structure should provide a compact, highly efficient method of nonlinear optical conversion. In particular, a structure designed to convert light at 980 nm to light at 1.55 mum is predicted to have a threshold intensity of 4.9 MW/cm(2), which is comparable to thresholds observed in parametric oscillators which use periodically poled lithium niobate.