Chalcogenide glasses for mid-IR photonic applications

The 3-15 μm range is a key region for a large number of applications in diverse areas such as biology and medicine, molecular spectroscopy, ground based and space borne environmental monitoring but also an important issue of instrumentation for astronomy and astrophysics to achieve complex but very reliable instruments. Going to the mid IR region is crucial for the observation of warm objects around 300 K and the characterization of their spectral features, considered as signatures for biological activity (e.g. water, ozone, carbon dioxide). Most infrared signatures or "fingerprints" (fundamental transitions) of organic species and biomolecules are essentially located in this spectral window. Thus, infrared spectroscopy is a powerful tool for detecting and determining the composition of complex samples; it is simple, reliable, fast, cost-efficient and non-destructive method. Then, it is crucial to be able to work at the extension toward thermal IR waveguides, where chalcogenide glasses provide promising properties, specifically their extended optical transmission window from the visible to the far infrared (up to 20 μm)