光通信、センシング、太陽系外惑星探査への応用に道を拓くデバイス Device opens the door to applications in optical communications, sensing, and the search for exoplanets
2022-09-07 ハーバード大学
2つのアプローチ（結合共振器と電気光学周波数コム）を組み合わせることで、帯域幅を犠牲にすることなく、効率を大幅に改善できることを実証した。
この新コムは、超高速のフェムト秒パルスを高出力で発生させることができる。高効率、広帯域と合わせて、天文学、光コンピューティング、測距、光計測などの用途に有用なデバイスとなる可能性がある。
＜関連情報＞
- https://www.seas.harvard.edu/news/2022/09/new-chip-frequency-comb-100x-more-efficient
- https://www.nature.com/articles/s41566-022-01059-y
高効率・広帯域のオンチップ光周波数コム発生器 High-efficiency and broadband on-chip electro-optic frequency comb generators
Yaowen Hu,Mengjie Yu,Brandon Buscaino,Neil Sinclair,Di Zhu,Rebecca Cheng,Amirhassan Shams-Ansari,Linbo Shao,Mian Zhang,Joseph M. Kahn & Marko Lončar
Nature Photonics Published:29 August 2022
DOI:https://doi.org/10.1038/s41566-022-01059-y
Abstract
Developments in integrated photonics have led to stable, compact and broadband comb generators that support a wide range of applications including communications1, ranging2, spectroscopy3, frequency metrology4, optical computing5,6 and quantum information7,8. Broadband optical frequency combs can be generated in electro-optical cavities, where light passes through a phase modulator multiple times while circulating in an optical resonator9,10,11,12. However, broadband electro-optic frequency combs are currently limited by low conversion efficiencies. Here we demonstrate an integrated electro-optic frequency comb with a conversion efficiency of 30% and an optical span of 132 nm, based on a coupled-resonator platform on thin-film lithium niobate13. We further show that, enabled by the high efficiency, the device acts as an on-chip femtosecond pulse source (336 fs pulse duration), which is important for applications in nonlinear optics, sensing and computing. As an example, in the ultrafast and high-power regime, we demonstrate a frequency comb with simultaneous electro-optic and third-order nonlinearity effects. Our device paves the way for practical optical frequency comb generators and provides a platform to investigate new regimes of optical physics that simultaneously involve multiple nonlinearities.
