Broadband Optical Spectrum Downconversion to RF Using Integrated Dual-Comb Source

Combining all the benefits of Fourier transform infrared (FTIR) spectroscopy in a chip scale spectroscopic sensor looks promising for mobile and wearable platform development. Dual-comb spectroscopy enables downconversion of optical absorption spectra into the RF range for fast measurement using single photodetector [1] . Some cases of dual-comb spectroscopy based on laser-pumped MRs were successfully demonstrated [2] – [4] . The early attempts at combining LD-pumped integrated frequency combs into dual-comb were also reported [5] . However, to demonstrate viability of the technology for applications, it is important to integrate LD and SiN-chip with the MR into the compact autonomously operated device generating at least one optical frequency comb.