Time-stepped optical frequency comb laser design leveraging three-dimensional integration of thin-film lithium niobate and silicon CMOS

We present a framework for designing high-performance Time-Stepped Optical Frequency Comb (TSOFC) lasers comprising: (i) Thin Film Lithium Niobate (TFLN) Integrated Circuit (IC) for high-bandwidth photonic devices; (ii) Semiconductor Optical Amplifier for optical gain; (iii) silicon CMOS IC for drive circuits; and (iv) three-dimensional integration for dense connectivity between CMOS and TFLN. We target high-resolution Optical Coherence Tomography (OCT) as an example application; our TSOFC design switches between 128 optical wavelengths at 3 GHz switching rate (to meet lateral, axial, and temporal resolution requirements) with <2 Watts total system power consumption (using a 180 nm technology node for CMOS IC).