CMOS-compatible integrated optical hyper-parametric oscillator

TLDR: In this article, a fully integrated, CMOS-compatible, multiple-wavelength source with high differential slope efficiency at only a few tens of milliwatts of continuous-wave power is presented.

Abstract: Integrated multiple-wavelength laser sources, critical for important applications such as high-precision broadband sensing and spectroscopy1, molecular fingerprinting2, optical clocks3 and attosecond physics4, have recently been demonstrated in silica and single-crystal microtoroid resonators using parametric gain2,5,6. However, for applications in telecommunications7 and optical interconnects8, analogous devices compatible with a fully integrated platform9 do not yet exist. Here, we report a fully integrated, CMOS-compatible, multiple-wavelength source. We achieve optical ‘hyper-parametric’ oscillation in a high-index silica-glass microring resonator10 with a differential slope efficiency above threshold of 7.4% for a single oscillating mode, a continuous-wave threshold power as low as 54 mW, and a controllable range of frequency spacing from 200 GHz to more than 6 THz. The low loss, design flexibility and CMOS compatibility of this device will enable the creation of multiple-wavelength sources for telecommunications, computing, sensing, metrology and other areas. Through optical ‘hyper-parametric’ oscillation in a high-index silica glass microring resonator, scientists demonstrate a fully integrated CMOS-compatible low-loss multiple-wavelength source that has high differential slope efficiency at only a few tens of milliwatts of continuous-wave power. The achievement has significant implications for telecommunications and on-chip optical interconnects in computers.