Dispersion spectroscopy with optical frequency comb-based single-shot dual-heterodyne mixing

We present a novel approach to high-speed dispersion spectroscopy that realizes a wide dynamic range, by simultaneous and parallel phase measurement using scanless dual-heterodyne mixing of 50 and 1.4 GHz frequency intervals. This system can realize parallel measurements of the relative phases between adjacent frequencies by introducing an optical frequency comb and intensity modulator to generate adjacent frequency and arrayed waveguide grating to separate the sidebands. The experimental results using single-mode fibers, whose lengths range from 0 to 92 km, indicated a 26 nm dispersion spectrum, 1785 ps/nm measurement range, and 0.27 ps/nm measurement uncertainty in 1 ms. (C) 2019 Optical Society of America