Abstract

Free-space optics (FSO) in the mid-infrared (mid-IR) contains rich spectral resources for future ultrahigh-speed wireless communications yet is currently under-exploited. Two atmospheric transmission windows at the mid-IR, namely, the mid-wave IR (MWIR, 3–5 μm) and the long-wave IR (LWIR, 8–12 μm), show great potential in supporting free-space communications for both terrestrial and space application scenarios. Particularly, the LWIR signal with a longer wavelength has high intrinsic robustness against aerosols’ scattering and turbulence-induced scintillation and beam broadening effects, which are the main concerns hindering the wide deployment of practical FSO systems. In this context, high-bandwidth semiconductor-based mid-IR FSO transceivers will be desirable to meet the requirements of low energy consumption and small footprints for large-volume development and deployment. Quantum cascade devices, including quantum cascade lasers (QCLs) and quantum cascade detectors (QCDs), appear promising candidates to fulfill this role. In this work, we report a high-speed LWIR FSO transmission demonstration with a 9.6-μm directly-modulated (DM)-QCL and a fully passive QCD without any active cooling or bias voltage. Up to 8 Gb/s, 10 Gb/s, and 11 Gb/s signal transmissions are achieved when operating the DM-QCL at 10 °C, 5 °C, and 0 °C, respectively. These results indicate a significant step towards an envisioned fully-connected mid-IR FSO solution empowered by the quantum cascade semiconductor devices.

High-speed quantum cascade detector characterized with a mid-infrared femtosecond oscillator

Johannes Hillbrand, Léonard Matthieu Krüger, Sandro Dal Cin, Hedwig Knötig, Jonas Heidrich, Aaron Maxwell Andrews, Gottfried Strasser, Ursula Keller, and Benedikt Schwarz
Opt. Express 29(4) 5774-5781 (2021)

High bitrate data transmission in the 8-14 µm atmospheric window using an external Stark-effect modulator with digital equalization

Hamza Dely, Mahdieh Joharifar, Xiaodan Pang, Djamal Gacemi, Toms Salgals, Richard Schatz, Yan-Ting Sun, Thomas Bonazzi, Etienne Rodriguez, Yanko Todorov, Angela Vasanelli, Aleksejs Udalcovs, Sandis Spolitis, Vjaceslavs Bobrovs, Oskars Ozolins, Sergei Popov, and Carlo Sirtori
Opt. Express 31(5) 7259-7264 (2023)

Characterization of noise regimes in mid-IR free-space optical communication based on quantum cascade lasers

Marco Seminara, Tecla Gabbrielli, Nicola Corrias, Simone Borri, Luigi Consolino, Marco Meucci, Paolo De Natale, Francesco Cappelli, and Jacopo Catani
Opt. Express 30(25) 44640-44656 (2022)

Interband cascade technology for energy-efficient mid-infrared free-space communication

Pierre Didier, Hedwig Knötig, Olivier Spitz, Laurent Cerutti, Anna Lardschneider, Elie Awwad, Daniel Diaz-Thomas, A. N. Baranov, Robert Weih, Johannes Koeth, Benedikt Schwarz, and Frédéric Grillot
Photon. Res. 11(4) 582-590 (2023)

Free-space transmission of picosecond-level, high-speed optical pulse streams in the 3 µm band

Yulong Su, Wenlong Tian, Yang Yu, Jiacheng Meng, Yunqiang Zheng, Shuaiwei Jia, Zhuang Xie, Yishan Wang, Jiangfeng Zhu, and Wei Wang
Opt. Express 31(17) 27433-27449 (2023)