PHOTONIC INTEGRATED CIRCUIT WITH SQUEEZED AND ENTANGLED LIGHT GENERATION, AND ASSOCIATED METHODS

摘要

A photonic integrated circuit (PIC) includes a first microresonator that generates a two-mode squeezed vacuum using spontaneous four-wave mixing. Specifically, the first microresonator uses a nonlinear optical medium to convert two pump photons into a pair of entangled signal and idler photons. Due to imperfect conversion efficiency, some of the pump light may co-propagate with the signal light and idler light. To remove this "unconverted" pump light, the PIC includes a second microresonator that is tuned to resonate with only the pump light. The second microresonator is located after the first microresonator and couples the unconverted pump light into a waveguide that guide the light off the PIC. Thus, the second microresonator acts as a notch filter. Integrating this pump filter onto the PIC adds negligibly to the path length of the squeezed light, and therefore saves the propagation losses incurred when using a much larger off-chip filter.