Packaged foundry-fabricated silicon spiral photon pair source

Abstract

We have demonstrated a packaged Silicon photon pair source. The spiral silicon waveguide source is 500 nm x 220 nm x 2 cm long and was packaged with input/output optical fibers enabling turn-key generation of photon pairs by connecting the input optical fiber to a telecommunication grade laser. In this work, we experimentally characterized the generation of bi-photons by spontaneous four-wave mixing in the Silicon waveguide. The insertion loss of the chip, after packaging, was measured to be approximately 15 dB (3 dB/facet, waveguide propagation loss of less than 1.5 dB/cm, 6 dB from splitters sequence). We investigated the phase matching of the source by wavelength tuning the 1 nm bandpass filters and found that the generated bi-photons have a half-bandwidth of 10 nm about the pump wavelength. We investigate pulse pumping using an actively mode-locked fiber laser with a 500 MHz repetition rate, pulse duration of approximately 30 ps and peak pulse power of 400 mW. Excitation of the pulsed source with a power of 1.4 mW through the chip generated 300 kHz coincidence rates after passing the chip’s output through a series of spectral bandpass filters (-1.4 db in channel 1 and -2.4 dB in channel 2 of filter loss and approximately 85 % efficiency of the detectors: inferred on-chip pair generation rate of 58 MHz). We also investigate two sources with 6 mW of continuous-wave pump power to generate 1550 nm bi-photons, generating 6.0 kHz coincidence rates (inferred on-chip pair generation rate of 2.3 MHz).