Efficient telecom-to-visible spectral translation through ultralow power nonlinear nanophotonics

• Published in: Nature photonics 2019-09, Vol.13 (9), p.593-601
• Main Authors: Lu, Xiyuan, Moille, Gregory, Li, Qing, Westly, Daron A., Singh, Anshuman, Rao, Ashutosh, Yu, Su-Peng, Briles, Travis C., Papp, Scott B., Srinivasan, Kartik
• Format: Article
• Language: English
• Subjects: 639/624/1075/1079; 639/624/1075/187; 639/624/399/1097; 639/624/400/1021; 639/624/400/385; Applied and Technical Physics; Continuous radiation; Four-wave mixing; Lasers; Nanofabrication; Nonlinear response; Nonlinear systems; Physics; Physics and Astronomy; Quantum Physics; Silicon nitride; Spectra; Telecommunications; Translation; Wavelengths
• ISSN: 1749-4885; 1749-4893
• DOI: 10.1038/s41566-019-0464-9

The ability to spectrally translate lightwave signals in a compact, low-power platform is at the heart of the promise of nonlinear nanophotonic technologies. For example, a device to connect the telecommunications band with visible and short near-infrared wavelengths can enable a connection between high-performance chip-integrated lasers based on scalable nanofabrication technology with atomic systems used for time and frequency metrology. Although second-order nonlinear ( χ (2) ) systems are the natural approach for bridging such large spectral gaps, here we show that third-order nonlinear ( χ (3) ) systems, despite their typically much weaker nonlinear response, can realize spectral translation with unprecedented performance. By combining resonant enhancement with nanophotonic mode engineering in a silicon nitride microring resonator, we demonstrate efficient spectral translation of a continuous-wave signal from the telecom band (~1,550 nm) to the visible band (~650 nm) through cavity-enhanced four-wave mixing. We achieve such translation over a wide spectral range >250 THz with a translation efficiency of (30.1 ± 2.8)% and using an ultralow pump power of (329 ± 13) μW. The translation efficiency projects to (274 ± 28)% at 1 mW and is more than an order of magnitude larger than what has been achieved in current nanophotonic devices. Combining resonant enhancement with nanophotonic mode engineering in a silicon nitride microring resonator allows spectral translation of a continuous-wave signal from the telecom band (~1,550 nm) to the visible band (~650 nm) through cavity-enhanced four-wave mixing with a translation efficiency of (30.1 ± 2.8)% at a pump power of (329 ± 13) μW.