Title: Microresonator soliton dual-comb imaging [Optica 6 (9), 1110-1116 (2019), PDF]

Authors: Chengying Bao, Myoung-Gyun Suh, and Kerry Vahala

Submitted on 27 Aug 2019.

Abstract: Fast-responding detector arrays are commonly used for imaging rapidly changing scenes. Besides array detectors, a single-pixel detector combined with a broadband optical spectrum can also be used for rapid imaging by mapping the spectrum into a spatial coordinate grid and then rapidly measuring the spectrum. Here, optical frequency combs generated from high-𝑄 silica microresonators are used to implement this method. The microcomb is dispersed in two spatial dimensions to measure a test target. The target-encoded spectrum is then measured by multi-heterodyne beating with another microcomb having a slightly different repetition rate, enabling an imaging frame rate up to 200 kHz and fill rates as high as 48 megapixels/s. The system is used to monitor the flow of microparticles in a fluid cell. Microcombs in combination with a monolithic waveguide grating array imager could greatly magnify these results by combining the spatial parallelism of detector arrays with spectral parallelism of optics.