Optimizing photon-pair generation electronically using a p-i-n diode incorporated in a silicon microring resonator

Abstract

Silicon photonic microchips may be useful for compact, inexpensive, room-temperature optically pumped photon-pair sources, which unlike conventional photon-pair generators based on crystals or optical fibers, can be manufactured using CMOS-compatible processes on silicon wafers. It has been shown that photon pairs can be created in simple structures such as microring resonators at a rate of a few hundred kilohertz using less than a milliwatt of optical pump power, based on the process of spontaneous four-wave mixing. To create a practical photon-pair source, however, also requires some way of monitoring the device and aligning the pump wavelength when the temperature varies, since silicon resonators are highly sensitive to temperature. In fact, monitoring photodiodes are standard components in classical laser diodes, but the incorporation of germanium or InGaAs photodiodes would raise the cost and fabrication complexity. Here, we present a simple and effective all-electronic technique for finding the optimum operating point for the microring used to generate photon pairs, based on measuring the reverse-biased current in a silicon p-i-n junction diode fabricated across the waveguide that constitutes the silicon microring. We show that by monitoring the current, and using it to tune the pump laser wavelength, the photon-pair generation properties of the microring can be preserved over a temperature range of more than 30 °C.

High-rate photon pairs and sequential Time-Bin entanglement with Si3N4 microring resonators

“…Additionally, we exploit a Si 3 N 4 MRR to demonstrate a high repetition rate sequential Time-Bin scheme [36] well suited for quantum communication applications. The MRR under test has a Q-factor of 4.6 × 10 5 , which gives a good trade-off between brightness and stability: higher Q-factors lead to brighter sources but narrower resonance linewidths, and hence, are more challenging to maintain on-resonance without sophisticated stabilisation schemes [27,37]. This also results in relatively short coherence times allowing for high repetition rates, e.g.…”

Silicon photonic entangled photon-pair and heralded single photon generation with CAR > 12,000 and g^(2)(0) < 0006

“…The intrinsic rate of nonlinear optical processes increases as the mode volume decreases, which reduces the pump power requirements of silicon microrings used for pair generation to sub-milliwatt levels 8 , and the device footprint to about one hundred square-microns 2,3 . Silicon device technology is useful not only for making high quality factor (Q) compact optical micro-resonators such as microrings and microdisks, but also driving and monitoring them with the help of micro-electronic components 10,11 . Also, the larger free-spectral range (FSR) compared to glass or silicon nitride micro-resonators (in the few-nanometer range) makes it easier to extract and measure the signal and idler photons from the "comb-like" multiplexed state where many wavelength-pairs are simultaneously generated 12 , since the required components can be selected from commercially-available devices (such as filters, de-multiplexers, arrayed waveguide gratings, delay line interferometers etc.)…”

Silicon Quantum Photonics

“…Multiple types of resonator-based sources have also been investigated: single-ring resonators [30], [35], [47]- [51] (Fig. 4c), including studies of the effect on reverse bias PIN junctions for mitigating FCA [30], [52] (Fig. 2b); ring resonators in a self-locking double-bus configuration [53] (Fig.…”