Vernier spectrometer using counterpropagating soliton microcombs

Qi-Fan Yang; Boqiang Shen; Heming Wang; Minh Tran; Zhewei Zhang; Ki Youl Yang; Lue Wu; Chengying Bao; John Bowers; Amnon Yariv; Kerry Vahala

doi:10.1126/science.aaw2317

Vernier spectrometer using counterpropagating soliton microcombs

Science. 2019 Mar 1;363(6430):965-968. doi: 10.1126/science.aaw2317. Epub 2019 Feb 21.

Authors

Qi-Fan Yang¹, Boqiang Shen¹, Heming Wang¹, Minh Tran², Zhewei Zhang¹, Ki Youl Yang^{1

3}, Lue Wu¹, Chengying Bao¹, John Bowers², Amnon Yariv¹, Kerry Vahala⁴

Affiliations

¹ T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA 91125, USA.
² Department of Electrical and Computer Engineering, University of California, Santa Barbara, CA 93106, USA.
³ E. L. Ginzton Laboratory, Stanford University, Stanford, CA 94305, USA.
⁴ T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA 91125, USA. vahala@caltech.edu.

PMID: 30792361
DOI: 10.1126/science.aaw2317

Abstract

Determination of laser frequency with high resolution under continuous and abrupt tuning conditions is important for sensing, spectroscopy, and communications. We show that a single microresonator provides rapid and broadband measurement of optical frequencies with a relative frequency precision comparable to that of conventional dual-frequency comb systems. Dual-locked counterpropagating solitons having slightly different repetition rates were used to implement a vernier spectrometer, which enabled characterization of laser tuning rates as high as 10 terahertz per second, broadly step-tuned lasers, multiline laser spectra, and molecular absorption lines. Besides providing a considerable technical simplification through the dual-locked solitons and enhanced capability for measurement of arbitrarily tuned sources, our results reveal possibilities for chip-scale spectrometers that exceed the performance of tabletop grating and interferometer-based devices.