Sub-Minute Response Time of a Hollow-Core Photonic Bandgap Fiber Gas Sensor

Abstract

A hollow-core photonic bandgap (PBG) fiber sensing configuration for optical absorption spectroscopy of multiple-component gas samples absent of a vacuum environment is presented. Pressure-driven sensor response times that are shorter in duration compared to diffusion-limited filling times for fiber lengths ${>}1$ m are reported. Reduced filling times that approach the sub-minute regime are possible for a ${\sim} {\hbox {2}}$ meter length of commercially available PBG fiber with a 12.5 micron core diameter at a pressure ${<}15$ Psi. The spectroscopy measurements were limited to the near-IR region for sample gases that include acetylene and carbon dioxide. Using the techniques presented, the detection of concentrations ${<}100$ ppm for acetylene gas at pressures ${<}15$ Psi is possible.

© 2009 IEEE