Mid-IR supercontinuum generation in high numerical aperture chalcogenide fibers for environmental monitoring

The mid-IR wavelength range, and the fundamental vibrational absorption fingerprint region it encompasses, can be utilised for a variety of environmental and medical monitoring applications requiring the detection of specific covalently bonded molecules, for example, in atmosphere or in a patient's breath. Mid-IR transmitting chalcogenide fibres, based on the elements: sulfur, selenium, and tellurium, have a characteristically high optical non-linearity and thus can be tailored to also generate mid-IR supercontinuum light that covers this fingerprint region. The process of designing, fabricating, and characterising chalcogenide glass fibres via differential scanning calorimetry, microscopy, ellipsometry, and optical fibre loss measurements is detailed.