Yang Fan, Tan Yanzhen, Jin Wei, Lin Yuechuan, Qi Yun, Ho Hoi Lut
Opt Lett. 2016 Jul 1;41(13):3025-8. doi: 10.1364/OL.41.003025.
A highly sensitive, compact, and low-cost trace gas sensor based on photothermal effect in a hollow-core fiber Fabry-Perot interferometer (FPI) is described. The Fabry-Perot sensor is fabricated by splicing a piece of hollow-core photonic bandgap fiber (HC-PBF) to single-mode fiber pigtails at both ends. The absorption of a pump beam in the hollow core results in phase modulation of probe beam, which is detected by the FPI. Experiments with a 2 cm long HC-PBF with femtosecond laser drilled side-holes demonstrated a response time of less than 19 s and noise equivalent concentration (NEC) of 440 parts-per-billion (ppb) using a 1 s lock-in time constant, and the NEC goes down to 117 ppb (2.7×10 in absorbance) by using 77 s averaging time.
本文描述了一种基于空心光纤法布里-珀罗干涉仪（FPI）光热效应的高灵敏度、紧凑型且低成本的痕量气体传感器。该法布里-珀罗传感器通过将一段空心光子带隙光纤（HC-PBF）两端与单模光纤尾纤熔接而成。泵浦光束在空心光纤中的吸收导致探测光束的相位调制，由FPI进行检测。使用飞秒激光在2厘米长的HC-PBF上钻出侧孔进行实验，在1秒锁定时间常数下，响应时间小于19秒，噪声等效浓度（NEC）为440十亿分之一（ppb），通过77秒平均时间，NEC降至117 ppb（吸光度为2.7×10）。
