Mid-infrared gas sensing using a photonic bandgap fiber.
We demonstrate methane sensing based on Fourier transform infrared spectroscopy using a hollow-core photonic bandgap fiber guiding in the mid-infrared and idler pulses from a femtosecond optical parametric oscillator. Transmission measurements are presented for several fibers, and sensing is demonstrated using a fiber whose bandgap overlaps the methane fundamental absorption lines. The gas filling process of the air core is described, and qualitative methane concentrations measurements to 1000 ppm (parts in 10(6)) are reported. Operation down to 50 ppm based on our current experiment is predicted.
Gayraud
Nicolas
N
Applied Optics and Photonics Group, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK.
Kornaszewski
Ukasz W
UW
Stone
James M
JM
Knight
Jonathan C
JC
Reid
Derryck T
DT
Hand
Duncan P
DP
MacPherson
William N
WN