Real-time spectral interleaved electro-optic dual-comb spectroscopy

Abstract

Optical frequency comb with evenly spaced lines over a broad bandwidth has revolutionized the fields of optical metrology and spectroscopy. Here, we propose an electro-optic dual-comb spectroscopy to real-time interleave the spectrum with high resolution, in which two electro-optic frequency combs are seed by swept light source. An interleaved spectrum with a high resolution is real-time recorded by the sweeping probe comb without gap time, which is multi-heterodyne detected by the sweeping local comb. The proposed scheme measures a spectrum spanning 304 GHz in 1.6 ms with a resolution of 1 MHz, and reaches a spectral sampling rate of 1.9*108 points/s under Nyquist-limitation. A reflectance spectrum is measured with a calculated figure-of-merit of 4.2*108, which shows great prospect for fast and high-resolution applications.