2025-07-09 ハーバード大学
＜関連情報＞
- https://seas.harvard.edu/news/2025/07/tunable-laser-light
- https://opg.optica.org/optica/fulltext.cfm?uri=optica-12-7-985&id=574056
連続的かつ広範囲にチューニング可能な半導体リングレーザー Continuously and widely tunable semiconductor ring lasers
Johannes Fuchsberger, Theodore P. Letsou, Dmitry Kazakov, Rolf Szedlak, Federico Capasso, and Benedikt Schwarz
Optica Published: July 9, 2025
DOI:https://doi.org/10.1364/OPTICA.559884
Abstract
Tunable semiconductor lasers are indispensable for applications ranging from spectroscopy to telecommunications, yet achieving continuous, mode-hop-free tuning across broad frequency ranges in a compact, robust device remains challenging. Here, we present a ring-array quantum cascade laser (QCL) architecture that combines the single-mode, smooth tuning of distributed feedback lasers with an extended tuning range greater than 10cm−1, all within a compact chip-scale format. Our ring-array laser employs multiple small, independently addressable ring QCLs. These rings, coupled to a shared bus waveguide, have different radii, resulting in distinct lasing frequencies. This configuration enables multi-ring spectral sweeps with stable emission facilitated by unidirectional lasing. In contrast to traditional tunable lasers, our device achieves mode-hop-free tuning over broad bandwidths, is resilient under high levels of optical feedback, and supports beam combining for broadband spectral coverage, resulting in a combined tuning range of 33cm−1 from three different rings. This versatile platform offers a pathway for scalable, compact spectroscopic sources, with potential applications across the mid-infrared and beyond.
