Methane sensing at 1300 nm band with hollow-core photonic bandgap fibre as gas cell

Abstract

The feasibility of employing a hollow-core photonic bandgap fibre (HC-PBF) to measure methane concentrations below its lower explosive limit is assessed. Using a 5.6 m-long HC-PBF as gas cell, the spectrum of methane at ν2+2ν3 band at 1300 nm has been recorded and the Q-branch at 1331.55 nm selected for sensing purposes. A minimum detectivity of 49 ppmv-m for the system configuration is estimated.