Vernier spectrometer using counterpropagating soliton microcombs

Abstract

Making a (precision) measure of light When measuring length, we learn in school that a vernier scale that uses two rulers, slightly offset, can reduce human estimation error and improve the resolution of a measurement. Yang et al. apply the same vernier principle with optical combs to develop a spectrometer that can determine the wavelength of light with high accuracy and precision. Two phase-locked counterpropagating optical microcombs generated in a miniature microresonator provided the rulers. Matching up of the “teeth” of the combs was then used to measure the wavelength of the optical light sources. Science , this issue p. 965