Broadband difference frequency generation in periodically-poled thin-film lithium niobate

We demonstrate broadband difference frequency generation by dispersion engineering in periodically-poled thin-film lithium niobate waveguides. In simulations, we show tunable signal bandwidth from 30 nm to 300 nm. Experimentally, we achieve idler generation for signal wavelengths from 1320 nm to 1660 nm including temperature tuning.