2023-12-08 カリフォルニア工科大学(Caltech)
◆ULLニトライドは非常に純粋で、薄い膜に堆積されたシリコンと窒素から成る化合物で、これにより非常に低い電力で動作する短い光パルスデバイスが製造可能です。
◆ULLニトライドは通常分散を持ち、短い光パルスの生成を妨げるため、新しいマイクロコムブが必要でした。しかし、ULLニトライドを使用した新しいマイクロコムブは、光パルスをペアで生成することで通常分散の克服に成功し、将来的にはスマートフォンのような携帯デバイスに統合される可能性があります。
＜関連情報＞
- https://www.caltech.edu/about/news/conjoined-racetracks-make-new-optical-device-possible
- https://www.nature.com/articles/s41566-023-01257-2
正常分散マイクロ共振器における多色ソリトンパルスペア Soliton pulse pairs at multiple colours in normal dispersion microresonators
Zhiquan Yuan,Maodong Gao,Yan Yu,Heming Wang,Warren Jin,Qing-Xin Ji,Avi Feshali,Mario Paniccia,John Bowers & Kerry Vahala
Nature Photonics Published:03 August 2023
DOI:https://doi.org/10.1038/s41566-023-01257-2
Abstract
Soliton microcombs are helping to advance the miniaturization of a range of comb systems. These combs mode lock through the formation of short temporal pulses in anomalous dispersion resonators. Here, a new microcomb is demonstrated that mode locks through the formation of pulse pairs in coupled normal dispersion resonators. Unlike conventional microcombs, pulses in this system cannot exist alone, and instead phase lock in pairs wherein pulses in each pair feature different optical spectra. The pairwise mode-locking modality extends to multiple pulse pairs and beyond two rings, and it greatly constrains mode-locking states. Two- (bipartite) and three-ring (tripartite) states containing many pulse pairs are demonstrated, including crystal states. Pulse pairs can also form at recurring spectral windows. We obtained the results using an ultra-low-loss Si3N4 platform that has not previously produced bright solitons on account of its inherent normal dispersion. The ability to generate multicolour pulse pairs over multiple rings is an important new feature for microcombs. It can extend the concept of all-optical soliton buffers and memories to multiple storage rings that multiplex pulses with respect to soliton colour and that are spatially addressable. The results also suggest a new platform for the study of topological photonics and quantum combs.
