Waveguide resonators as squeezed light sources

Squeezed light forms the foundation of continuous-variable quantum optics. In most experimental realisations, bulk optics resonators utilising the second-order nonlinearity serve as the source of stable, high levels of squeezing. As one would expect, there is a drive towards producing squeezed light sources in integrated platforms, as it is expected that such a transition will ease the challenges in moving toward real-world applications. However, waveguides come with their own set of challenges; they generally exhibit increased losses, and some platforms suffer from photothermal or photorefractive effects.