New micro-optic cell for optical fibre gas sensorswith interferometric noisereduction

Abstract

A novel design of a micro-optic cell employing inexpensive optics is demonstrated for reducing interferometric noise in optical fibre gas sensors. Compared with the traditional collimating cell, the insertion loss is significantly reduced and the overall signal-to-interferometric-noise ratio is improved by a factor of five in a methane sensor using second harmonic signal detection.