Infrared Materials, Technology and Applications
The visible range is a small part of the electromagnetic spectrum. Imaging beyond this range, in the infrared region for example, can give additional information. There are however very few materials transparent in the 8-12 µm region, which is the most used window for thermal imaging (night vision) as it corresponds to the maximum emission of bodies at room temperature. Germanium, a rare and expensive element, has very interesting optical properties with very high refractive index and very low chromatic dispersion between 8-12 µm. Another mostly used material is the polycrystalline ZnSe produced with the Chemical Vapour Deposition technique.
Chalcogenide glasses are glasses based on sulfur, selenium and tellurium. They have been intensively studied mainly due to its large optical transmission window from the visible to far infrared region. They can be easily molded into complex optical elements.
Infrared technology was initially developed mainly for defense applications such as night vision and weapon guidance. Today, more and more industrial applications including thermal imaging, chemical sensing, environment surveillance and medical diagnostic have been developed. Mass consumer applications, for examples, for mobile phone and for car driving assistance are now considered. For extending the application domain of the infrared technology, the main challenge is to lower the cost of the infrared detectors and infrared optics.
In this talk, the challenge of the infrared technology and its applications in different fields will be discussed.