Backscatter-Immune Injection-Locked Brillouin Laser in Silicon

Nils T. Otterstrom, Shai Gertler, Yishu Zhou, Eric A. Kittlaus, Ryan O. Behunin, Michael Gehl, Andrew L. Starbuck, Christina M. Dallo, Andrew T. Pomerene, Douglas C. Trotter, Anthony L. Lentine, Peter T. Rakich

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


As self-sustained oscillators, lasers possess the unusual ability to spontaneously synchronize. These nonlinear dynamics are the basis for a simple yet powerful stabilization technique known as injection locking, in which a laser's frequency and phase can be controlled by an injected signal. Because of its inherent simplicity and favorable noise characteristics, injection locking has become a workhorse for coherent amplification and high-fidelity signal synthesis in applications ranging from precision atomic spectroscopy to distributed sensing. Within integrated photonics, however, these injection-locking dynamics remain relatively untapped - despite significant potential for technological and scientific impact. Here, we demonstrate injection locking in a silicon photonic Brillouin laser. Injection locking of this monolithic device is remarkably robust, allowing us to tune the laser emission by a significant fraction of the Brillouin gain bandwidth. Harnessing these dynamics, we demonstrate amplification of small signals by more than 23 dB. Moreover, we demonstrate that the injection-locking dynamics of this system are inherently nonreciprocal, yielding unidirectional control and backscatter immunity in an all-silicon system. This device physics opens the door to strategies for phase-noise reduction, low-noise amplification, and backscatter immunity in silicon photonics.

Original languageEnglish (US)
Article number044042
JournalPhysical Review Applied
Issue number4
StatePublished - Oct 22 2020

ASJC Scopus subject areas

  • General Physics and Astronomy


Dive into the research topics of 'Backscatter-Immune Injection-Locked Brillouin Laser in Silicon'. Together they form a unique fingerprint.

Cite this