Squeezing in a LiNbO3 integrated optical waveguide circuit

We report on traveling-wave quadrature squeezing generated in an integrated optical circuit fabricated with periodically- poled lithium niobate waveguides. The device integrates a second- harmonic-generation stage, waveguide couplers, spatial mode filters, and a degenerate-optical-parametric-amplification stage. The integration promises to create a low power, compact, and simple source of wideband squeezed light. -1 dB of squeezing is directly measured using 20 ps pulses with peak powers near 6W.