Chemical Sensing
Chalcogenide fibers are well suited for chemical sensing applications since most molecular species vibrate in the infrared region. The chalcogenide fibers can be used in fiber optic chemical sensor systems for quantitative remote detection and identification. Examples of different sensing techniques include Quantum Cascade Laser (QCL) based molecular detection and imaging system, evanescent/ATR (attenuated total reflectance), diffuse reflectance and absorption spectroscopy. The diffuse reflectance and evanescent/ATR techniques are useful for samples that scatter or are opaque at the mid-infrared wavelengths, including oil, freon, soap, paints, polymer curing reactions, glucose/water, benzene and derivatives, chlorinated hydrocarbons, alcohols, carboxylic acids, aqueous acids, perfumes and pharmaceutical products.