Flexible delivery of broadband, 100  fs mid-infrared pulses in the water-absorption band using hollow-core photonic crystal fiber

作者：W. Lin, Zeqing Li, Yunhua Teng, Jiapeng Huang, Yun Zhao, Zhuozhao Luo, Weiyi Sun, C. Jiang, Ruochen Yin, Yu Zheng, X. Jiang, Z. Huang, W. He, Meng Pang · 发表于：Optica · 年份：2025 · DOI：10.1364/optica.558579 · 被引用次数：6 · 研究领域：Photonic Crystal and Fiber Optics、Advanced Fiber Optic Sensors、Optical Network Technologies

High-quality free-space and over-fiber transmission of mid-infrared light is limited by factors such as material-related absorption, diffraction, light leakage, and nonlinearity. Conventional vacuum apparatus can be utilized for high-quality laser-beam delivery to address these issues; however, the deployment of such apparatus would increase system complexity, which is detrimental to their practical applications. Here, we report the successful use of evacuated hollow-core photonic crystal fiber (PCF) to flexibly transmit ultrafast mid-infrared pulses over several meters, while preserving exceptional spatial, spectral, and temporal fidelities. The PCF was engineered to feature a low-loss transmission band within the water absorption range, and an evacuated 5 m length was used to transmit Watt-level, 100 fs pulses centered at ∼2.8µm. A comparison between free-space transmission and air-filled PCF highlights the superior performance of the evacuated hollow-core PCF, indicating its strong suitability for the flexible delivery of sub-ps laser pulses in the mid-infrared.