Study on Transmission Optical Fiber Hydrogen Sensor

Based on palladium´s hydrogen sensibility and its reversibility of absorbing hydrogen, a transmission optical fiber hydrogen sensor is demonstrated. We deposited thin palladium film on the end of a multi-mode optical fiber, using LED as light source, and using a big-diameter-core optical fiber to collect transmission light. When modulated light emitted from the LED is injected to the thin palladium film, part of the light is reflected and absorbed, the other part of the light transmits through the thin palladium film. We can get hydrogen concentration by detecting the intensity of the transmission light. Result of the experiment indicates that this kind of optical fiber hydrogen sensor has a good linearity and high sensitivity