GHz configurable photon pair generation from a silicon nonlinear interferometer

Low loss and high speed processing of photons is central to architectures for photonic quantum information. High speed switching enables non-deterministic photon sources and logic gates to be made deterministic, while the speed with which quantum light sources can be turned on and off impacts the clock rate of photonic computers and the data rate of quantum communication. Here we use lossy carrier depletion modulators in a silicon waveguide nonlinear interferometer to modulate photon pair generation at 1~GHz without exposing the generated photons to the phase dependent parasitic loss of the modulators. The super sensitivity of nonlinear interferometers reduces power consumption compared to modulating the driving laser. This can be a building block component for high speed programmabile, generalised nonlinear waveguide networks.