2025-09-12 カリフォルニア工科大学
The experimental setup shown here incorporates on-chip optical parametric oscillator (OPO) technology to generate a frequency comb of laser-like light covering a wide range of frequencies with very little input energy. In this image, the chip includes ~20 OPOs, and one of them is being tested. An optical fiber is shown to the left of the chip and a free-space objective to the right.Credit: Alireza Marandi
＜関連情報＞
- https://www.caltech.edu/about/news/uniting-the-light-spectrum-on-a-chip
- https://www.nature.com/articles/s41566-025-01753-7
超低しきい値ナノフォトニックパラメトリック発振器によるマルチオクターブ周波数コム Multi-octave frequency comb from an ultra-low-threshold nanophotonic parametric oscillator
Ryoto Sekine,Robert M. Gray,Luis Ledezma,Selina Zhou,Qiushi Guo & Alireza Marandi
Nature Photonics Published:12 September 2025
DOI:https://doi.org/10.1038/s41566-025-01753-7
Abstract
Ultra-broadband frequency combs coherently unite distant portions of the electromagnetic spectrum. They underpin discoveries in ultra-fast science and serve as the building blocks of modern photonic technologies. Despite tremendous progress in integrated sources of frequency combs, achieving multi-octave operation on chip has remained elusive mainly because of the energy demand of typical spectral broadening processes. Here we break this barrier and demonstrate multi-octave frequency comb generation using an optical parametric oscillator in nanophotonic lithium niobate with only femtojoules of pump energy. Leveraging this ultra-low threshold and dispersion engineering, we accessed a previously unexplored optical parametric oscillator regime that enables highly efficient and stable coherent spectral broadening. We achieve orders-of-magnitude reduction in the energy requirement compared with the other techniques, confirm the coherence of the comb, and present a path towards more efficient and wider spectral broadening. Our results pave the way for ultra-short-pulse and ultra-broadband on-chip nonlinear photonic systems for numerous applications.
