Quantum interference using photon pairs generated in a silicon waveguide

Heedeuk Shin, Cheol Shin Won, Kyung Deuk Park

Joshua W. Silverstone, Damien Bonneau, K. Ohira +12 more

Gary F. Sinclair

Quantum interference between identical photons lies at the heart of our plan to construct a silicon photonic quantum computer. Several ground-breaking experiments have demonstrated the on-chip interference between photons generated in spiral [1] and ring resonator [2] sources. However, these two-photon experiments have relied on detecting the simultaneous arrival of a pair of photons from either source. In order that such experiments can be scaled-up, we require the multiplexing of probabilistic photon pair sources into an on-demand single photon source [3]. A first step towards this is to demonstrate heralded single photons from different sources will retain the purity and indistinguishability required to interfere with high visibility [4]. In our work we examine photon pair production by spontaneous four-wave mixing in a silicon waveguide source and determine the factors that limit the heralded two-photon interference visibility. We present a novel approach to modelling this generation process using the joint- temporal amplitude and compare our results with experimental data. [1] On-chip quantum interference between silicon photon-pair sources, Nature Photonics 8, 104, (2014). [2] Qubit entanglement between ring-resonator photon-pair sources on a silicon chip, Nature Communications 6, 7948, (2015). [3] Active temporal and spatial multiplexing of photons, Optica 3, 127, (2016) [4] Indistinguishable photon pair generation using two independent silicon wire waveguides, New Journal of Physics 13, 065005, (2011).

Rodrigo Amorim, Peter David Girouard, Lars Grüner-Nielsen +3 more

We report a comprehensive characterization of photon-pair generation by spontaneous four-wave mixing in a partially deuterated amorphous silicon (a-Si:D) waveguide for C-band heralded single-photon generation. In a 3.3-mm-long strip waveguide pumped with a continuous-wave laser at telecom wavelengths, we measure an on-chip pair-generation rate of 3.1 × 10 6 pairs/s, a maximum coincidence-to-accidental ratio of 66, and a heralded second-order correlation g H (2) (0)=0.058±0.002, with these values obtained at different pump powers. We also demonstrate, to the best of our knowledge, the first observation of time-energy entanglement from an amorphous silicon waveguide, with a Franson interference visibility of 77±5%. The power scaling of the singles and accidental coincidences indicates a significant noise contribution that currently limits the source performance. Our results identify a-Si:D as a promising nonlinear platform for bright, integrated photon-pair sources and future hybrid quantum photonic circuits.

Rainer Kaltenbaek, B. Blauensteiner, Markus Aspelmeyer +1 more

Hiroki Takesue, Hiroshi Fukuda, Tai Tsuchizawa +4 more

We report the experimental generation of polarization entangled photon pairs based on spontaneous four-wave mixing in a silicon waveguide. Using a nano-scale silicon wire waveguide placed in a fiber loop, we obtained 1.5-microm band polarization entanglement with two-photon interference visibilities of >83%.