Xiaoxi Wang

Silicon photonic entangled photon-pair and heralded single photon generation with CAR > 12,000 and g (2) (0) < 0.006

We report measurements of time-frequency entangled photon pairs and heralded single photons at 1550 nm wavelengths generated using a microring resonator pumped optically by a diode laser. The conventional metrics used to describe performance, such as Coincidences-to-Accidentals Ratio (CAR), conditional self-correlation [g(2) (0) ], two-photon energy-time Franson interferometric visibility etc. are shown to reach a high-performance regime not yet achieved by silicon photonics, and attained previously only by crystal, glass and fiber-based pair-generation devices.

Compact silicon photonic resonance-assisted variable optical attenuator

A two-part silicon photonic variable optical attenuator is demonstrated in a compact footprint which can provide a high extinction ratio at wavelengths between 1520 nm and 1620 nm. The device was made by following the conventional p-i-n waveguide section by a high-extinction-ratio second-order microring filter section. The rings provide additional on-off contrast by utilizing a thermal resonance shift, which harvested the heat dissipated by current injection in the p-i-n junction. We derive and discuss a simple thermal-resistance model in explanation of these effects.