Hybrid Integrated Dual-Microcomb Source

Dual-comb interferometry is based on self-heterodyning two optical frequency combs, with corresponding mapping of the spectrum into radio-frequency domain. The dual comb enables diverse applications, including metrology, fast high-precision spectroscopy high signal-to-noise ratio, distance ranging, and coherent communications. However, current dual-frequency-comb systems are designed for research applications typically rely scientific equipment bulky mode-locked lasers. Here we demonstrate a fully integrated power-efficient dual-microcomb source that electrically driven allows turnkey operation. Our implementation uses commercially available components, distributed-feedback Fabry-Perot laser diodes, silicon-nitride photonic circuits microresonators fabricated in commercial multiproject wafer runs. devices therefore unique terms size, weight, power consumption, cost. Laser-diode self-injection locking relaxes requirements microresonator spectral purity $Q$ factor, so can generate soliton microcombs resilient to thermal drift pump-to-comb sideband efficiency up 40% at mW levels. We down-conversion from 1400 1700 nm domain, which valuable wide-band Fourier spectroscopy, was previously not chip-scale devices. findings pave way further integration miniature microcomb-based sensors high-volume thus opening prospect innovative products redefine market industrial consumer mobile wearable sensors.