Quasi-phasematched nonlinear interactions and devices

The field of nonlinear optics began nearly simultaneously in the United States and in Russia in 1962. The early years of discovery led to an understanding of nonlinearity in materials, phasematching, and nonlinear device performance. In the second decade of the 1970s, tunable parametric oscillators driven by high-peak-power Q-switched lasers made the transition to tools useful for spectroscopy and remote sensing. In the late 1980s engineered nonlinear materials were introduced with the successful implementation of quasi-phasematching by periodic inversion of ferroelectric domains in lithium niobate. Lithographic processing techniques enabled the fabrication of quasi-phasematched nonlinear "chips" using electric field poling of lithium niobate at the wafer scale.