Goldstein Jordan, Lin Hongtao, Deckoff-Jones Skylar, Hempel Marek, Lu Ang-Yu, Richardson Kathleen A, Palacios Tomás, Kong Jing, Hu Juejun, Englund Dirk
Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
State Key Laboratory of Modern Optical Instrumentation, College of Information Science and Electronic Engineering, Zhejiang University, 310027, Hangzhou, China.
Nat Commun. 2022 Jul 7;13(1):3915. doi: 10.1038/s41467-022-31607-7.
The development of compact and fieldable mid-infrared (mid-IR) spectroscopy devices represents a critical challenge for distributed sensing with applications from gas leak detection to environmental monitoring. Recent work has focused on mid-IR photonic integrated circuit (PIC) sensing platforms and waveguide-integrated mid-IR light sources and detectors based on semiconductors such as PbTe, black phosphorus and tellurene. However, material bandgaps and reliance on SiO substrates limit operation to wavelengths λ ≲ 4 μm. Here we overcome these challenges with a chalcogenide glass-on-CaF PIC architecture incorporating split-gate photothermoelectric graphene photodetectors. Our design extends operation to λ = 5.2 μm with a Johnson noise-limited noise-equivalent power of 1.1 nW/Hz, no fall-off in photoresponse up to f = 1 MHz, and a predicted 3-dB bandwidth of f > 1 GHz. This mid-IR PIC platform readily extends to longer wavelengths and opens the door to applications from distributed gas sensing and portable dual comb spectroscopy to weather-resilient free space optical communications.
开发紧凑且便于携带的中红外（mid-IR）光谱设备对于从气体泄漏检测到环境监测等应用的分布式传感而言是一项关键挑战。近期的工作主要集中在基于PbTe、黑磷和碲等半导体的中红外光子集成电路（PIC）传感平台以及波导集成的中红外光源和探测器上。然而，材料的带隙以及对SiO衬底的依赖将操作限制在波长λ≲4μm。在此，我们通过一种包含分裂栅光热石墨烯光电探测器的硫系玻璃-氟化钙PIC架构克服了这些挑战。我们的设计将操作扩展至λ = 5.2μm，具有约翰逊噪声限制的等效噪声功率为1.1 nW/Hz，在高达f = 1 MHz时光响应无下降，预计3 dB带宽f > 1 GHz。这种中红外PIC平台很容易扩展到更长波长，并为从分布式气体传感、便携式双梳光谱到耐候性自由空间光通信等应用打开了大门。
