Laser soliton microcombs on silicon

TL;DR

This paper demonstrates heterogeneously integrated silicon-based laser soliton microcombs on a chip, enabling scalable, low-cost production of coherent light sources for advanced photonic applications like high-speed data transmission and LiDAR.

Contribution

It introduces a CMOS-compatible method to produce laser soliton microcombs on silicon, combining InP/Si lasers with silicon nitride microresonators for the first time.

Findings

Achieved single-soliton microcombs with 100 GHz repetition rate.

Produced thousands of devices from a single wafer using standard CMOS processes.

Demonstrated electrical control of microcomb-laser phase for stable operation.

Abstract

Silicon photonics enables wafer-scale integration of optical functionalities on chip. A silicon-based laser frequency combs could significantly expand the applications of silicon photonics, by providing integrated sources of mutually coherent laser lines for terabit-per-second transceivers, parallel coherent LiDAR, or photonics-assisted signal processing. Here, we report on heterogeneously integrated laser soliton microcombs combining both InP/Si semiconductor lasers and ultralow-loss silicon nitride microresonators on monolithic silicon substrate. Thousands of devices are produced from a single wafer using standard CMOS techniques. Using on-chip electrical control of the microcomb-laser relative optical phase, these devices can output single-soliton microcombs with 100 GHz repetition rate. Our approach paves the way for large-volume, low-cost manufacturing of chip-based frequency combs for next-generation high-capacity transceivers, datacenters, space and mobile platforms.