介绍了一种基于光子晶体光纤(PCF)干涉仪的新型氢气传感器。该传感器采用反射式光路设计，在氢气传感单元中引入一段PCF。该PCF的一端以及一部分包层外壁在真空条件下蒸镀了一层金属钯膜，另一端接入光路，构成一套全光纤氢气传感系统。实验中记录了氢气浓度(体积分数)从0到5%变化时传感单元对应的干涉谐振波长的变化，谐振波长最大的移动可达1.2 nm，相比大多数基于布拉格光栅的光纤氢气传感器，相同条件下灵敏度有很大的提高。整套传感系统未引入任何分立的光学元件，在兼顾了全光纤光路的条件下，实现了较高的检测灵敏度。

A new method by introducing a photonic crystal fiber (PCF) inline interferometer for hydrogen sensing is demonstrated. The sensing unit contains a piece of PCF, constituting a reflection-type hydrogen sensing system. One end and the outer face of the PCF are plated with a thin palladium film under vacuum conditions, while the other end connects to the optical path. Therefore, a set of all-fiber hydrogen sensor is accomplished. Hydrogen concentration from 0 to 5% is detected in the experiment and the related interferometric resonant wavelength shift is recorded. The maximum wavelength shift is over 1.2 nm. Compared with hydrogen sensors based on fiber Bragg grating, the sensitivity of the experiment has great improvement. The whole system not only has an all-fiber optical path without any bulk-optic components, but also owns a high sensitivity.