Fiber-optic cavity sensing of hydrogen diffusion.
A novel type of fiber-optic cavity sensor for hydrogen diffusion into and out of fibers is presented. The sensor is an implementation of a cavity ringdown scheme in a silica-based single-mode fiber that has been exposed to gaseous hydrogen at normal pressure. The measured ringdown times during the H2 diffusion show good agreement with a theoretical diffusion model. This model allows the determination of the diffusion coefficient of hydrogen in silica, resulting in D = (3.02 +/- 0.07) x 10(-15) m2/s at 30 degrees C.
Vogler
Daniel E
DE
Swiss Federal Institute of Technology (ETH), Institute of Quantum Electronics, Laser Spectroscopy and Sensing Laboratory, Hoenggerberg HPF D23, CH-8093 Zurich, Switzerland. vogler@iqe.phys.ethz.ch
Müller
Michel G
MG
Sigrist
Markus W
MW