Mid-Infrared supercontinuum absorption spectroscopy beyond 7 µm based on free Arsenic chalcogenide fiber

Mid-Infrared methane (CH4) spectroscopy results were obtained in band III beyond 7 µm. To achieve this, the generation of supercontinuum covering the spectral range between 5 and 12 µm was realized by using purified chalcogenide optical fibers free of highly toxic elements such as arsenic and antimony. Besides a pumping with an optical parametric amplifier, an all fibered pumping scheme has also been investigated. In both configuration, supercontinuum absorption spectroscopy experiments have allowed for CH4 sensing, concentration as low as 14 ppm has been detected.