Milliwatt-threshold visible-telecom optical parametric oscillation using silicon nanophotonics
Xiyuan Lu, Gregory T. Moille, Anshuman Singh, Qing Li, Daron A. Westly, Ashutosh S. Rao, Su Peng Yu, Travis Briles, Scott B. Papp, Kartik A. Srinivasan
The on-chip creation of coherent light at visible wavelengths is of interest to many applications in spectroscopy, sensing, and metrology. Towards that goal, here we propose and demonstrate the first on-chip visible-telecom optical parameteric oscillator (OPO), using a whispering-gallery mode (WGM) cavity on a silicon photonics platform. In contrast to previous works that use WGM photonics to realize telecom-pumped OPOs with a wide spectral separation in the infrared, here we demonstrate a nanophotonic OPO that is pumped in the 900 nm band and generates signal and idler light in the 700 nm and 1300 nm bands, respectively. Moreover, our OPO has a superior power efficiency with a threshold power of (0.9 +/- 0.1) mW, which is more than 50x smaller than the WGM-based infrared OPOs. We further show how the device design can be modified to access other desirable spectral windows with a similar power efficiency, and generate 780 nm and 1500 nm band light using a 1020 nm band pump. Though further development is needed, our nanophotonic visible-telecom OPO shows distinct advantages in power efficiency, operation stability, and device scalability, and is a major advance in the on chip generation of coherent visible light.