Search for: All records

Abstract Kerr microcombs have drawn substantial interest as mass-manufacturable, compact alternatives to bulk frequency combs. This could enable the deployment of many comb-reliant applications previously confined to laboratories. Particularly enticing is the prospect of microcombs performing optical frequency division in compact optical atomic clocks. Unfortunately, it is difficult to meet the self-referencing requirement of microcombs in these systems owing to the approximately terahertz repetition rates typically required for octave-spanning comb generation. In addition, it is challenging to spectrally engineer a microcomb system to align a comb mode with an atomic clock transition with a sufficient signal-to-noise ratio. Here we adopt a Vernier dual-microcomb scheme for optical frequency division of a stabilized ultranarrow-linewidth continuous-wave laser at 871 nm to an ~235 MHz output frequency. This scheme enables shifting an ultrahigh-frequency (~100 GHz) carrier-envelope offset beat down to frequencies where detection is possible and simultaneously placing a comb line close to the 871 nm laser—tuned so that, if frequency doubled, it would fall close to the clock transition in¹⁷¹Yb⁺. Our dual-comb system can potentially combine with an integrated ion trap towards future chip-scale optical atomic clocks. 

We showcase a fully on-chip CMOS-fabricated silicon photonic integrated circuit employing a bidirectionally pumped microring and polarization splitter-rotators tailored for the generation of broadband (>9 THz), high-fidelity (90–98%) polarization-entangled photons. Spanning the optical C+L-band and producing over 116 frequency-bin pairs on a 38.4-GHz-spaced grid, this source is ideal for flex-grid wavelength-multiplexed entanglement distribution in multiuser networks. 

We demonstrate a silicon photonic integrated circuit fabricated through the CMOS manufacturing process, which features a bidirectionally pumped microring to achieve over 116 high-fidelity polarization entangled channels covering the entire optical C+L-band for flex-grid entanglement distribution. 

We report a demonstration of a 3-channel wavelength-selective switch with individual channel bandwidths of 2 GHz and drop port loss below 1 dB, paving the way for efficient spectrum utilization in quantum networking applications.