Laser-power consumption of soliton formation in a bidirectional Kerr resonator

TL;DR

This paper demonstrates a highly efficient, bidirectional Kerr resonator circuit that achieves near-unity power conversion efficiency for soliton frequency comb generation, advancing integrated photonics for high-speed data and sensing applications.

Contribution

It introduces a novel bidirectional Kerr resonator design with reflection control to enable efficient, one-sided soliton formation and high power conversion efficiency in integrated photonics.

Findings

Achieved 65% conversion efficiency from a 40 mW pump laser.

Demonstrated 97% of pump power consumed in soliton generation.

Enabled efficient, high-power soliton frequency combs in integrated circuits.

Abstract

Laser sources power extreme data transmission as well as computing acceleration, access to ultrahigh-speed signaling, and sensing for chemicals, distance, and pattern recognition. The ever-growing scale of these applications drives innovation in multi-wavelength lasers for massively parallel processing. We report a nanophotonic Kerr-resonator circuit that consumes the power of an input laser and generates a soliton frequency comb at approaching unit efficiency. By coupling forward and backward propagation, we realize a bidirectional Kerr resonator that supports universal phase matching but also opens excess loss by double-sided emission. Therefore, we induce reflection of the resonator's forward, external-coupling port to favor backward propagation, resulting in efficient, one-sided soliton formation. Coherent backscattering with nanophotonics provides the control to put arbitrary phase-matching and efficient laser-power consumption on equal footing in Kerr resonators. In the overcoupled-resonator regime, we measure 65% conversion efficiency of a 40 mW input pump laser, and the nonlinear circuit consumes 97% of the pump, generating the maximum possible comb power. Our work opens up high-efficiency soliton formation in integrated photonics, exploring how energy flows in nonlinear circuits and enabling laser sources for advanced transmission, computing, quantum sensing, and artificial-intelligence applications.