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. [ABSTRACT FROM AUTHOR]