Vernier spectrometer using counterpropagating soliton microcombs
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.
Additional Information© 2019 American Association for the Advancement of Science. Received 30 November 2018; accepted 7 February 2019. Published online 21 February 2019. Funding: Supported by the Defense Advanced Research Projects Agency (DARPA) under the SCOUT (W911NF-16-1-0548) and DODOS (HR0011-15-C-055) programs, the Air Force Office of Scientific Research (FA9550-18-1-0353), and the Kavli Nanoscience Institute. Author contributions: Experiments were conceived by Q.-F.Y., B.S., H.W., and K.V. Analysis of results was conducted by Q.-F.Y., B.S., H.W., and K.V. Measurements were performed by Q.-F.Y., B.S., and H.W. with assistance from M.T., Z.Z., L.W., and C.B. Silica resonators were fabricated by K.Y.Y. Test lasers and their setup were provided by M.T., Z.Z., J.B., and A.Y. All authors participated in writing the manuscript. The authors declare no competing financial interests. Data and materials availability: The datasets are available through Zenodo at http://doi.org/10.5281/zenodo.2542265.
Submitted - 1811.12925.pdf
Supplemental Material - aaw2317_Yang_SM.pdf