We demonstrate an on-chip single photon source that produces ultra-bright high-purity photon pairs in a comb fashion, achieving a spectral brightness of 6.24 × 107 pair/s/mW2/GHz which is the highest performance reported up to date.
Here we present the experimental demonstration of a Silicon ring resonator photon-pair source. The crystalline Silicon ring resonator (radius of 18.5μm) was designed to realize low dispersion across multiple resonances, which allows for operation with a high quality factor of Q~50k. In turn, the source exhibits very high brightness of >3x105 photons/s/mW2/GHz since the produced photon pairs have a very narrow bandwidth. Furthermore, the waveguidefiber coupling loss was minimized to <1.5dB using an inverse tapered waveguide (tip width of ~150nm over a 300μm length) that is butt-coupled to a high-NA fiber (Nufern UHNA-7). This ensured minimal loss of photon pairs to the detectors, which enabled very high purity photon pairs with minimal noise, as exhibited by a very high Coincidental-Accidental Ratio of >1900. The low coupling loss (3dB fiber-fiber) also allowed for operation with very low off-chip pump power of <200μW. In addition, the zero dispersion of the ring resonator resulted in the production of a photon-pair comb across multiple resonances symmetric about the pump resonance (every ~5nm spanning >20nm), which could be used in future wavelength division multiplexed quantum networks.
Integrated quantum photonics relies critically on the purity, scalability, integrability, and flexibility of a photon source to support diverse quantum functionalities on a single chip. Here we report a chip-scale photon-pair source on the silicon-on-insulator platform that utilizes dramatic cavity-enhanced four-wave mixing in a high-Q silicon microdisk resonator. The device is able to produce high-quality photon pairs at different wavelengths with a high spectral brightness of 6.24×10(7) pairs/s/mW(2)/GHz and photon-pair correlation with a coincidence-to-accidental ratio of 1386 ± 278 while pumped with a continuous-wave laser. The superior performance, together with the structural compactness and CMOS compatibility, opens up a great avenue towards quantum silicon photonics with capability of multi-channel parallel information processing for both integrated quantum computing and long-haul quantum communication.
Integrated quantum photonics relies critically on photon sources that have great purity, single-mode property, scalability, integrability and flexibility for both integrated quantum computing and long-haul quantum communication. Here we report a photon-pair/single-photon source that utilizes cavity-enhanced four-wave mixing in a high-Q silicon microresonator. The photon-pair source has a spectral brightness of 6:25 × 108 pairs/s/mW2/GHz and a quantum cross-correlation of g(2)si (0) = (2:58 ± 0:16) × 104. The generated photons are single-mode, with a quantum self-correlation of 1:87 ± 0:05. The heralded single photons has conditional photon autocorrelation gc(2) as low as 0:0075 ± 0:0017 at 5:9 × 104 pair/s.