Guest Lecture by Dr. Bharathi of IISc, Bengaluru

Dr. Bharathi from Prof. Umarji's laboratory, MRC department, IISc, Bengaluru gave a guest lecture on "Infrared detectors and Phase change materials “on Wednesday, March 15, 2017 at our Bidalur Campus.  The abstract of the lecture is- the requirement of night-vision or vision unobscured by fog and haze in various situations has lead to the development of thermal imaging technology. The phenomenon at the heart of this technology is the blackbody thermal radiation emitted by bodies that is proportional to their temperatures. For most applications, the thermal radiation lies in the middle infra-red (MIR) wavelengths, i.e., 3 µm to 20 µm.  Devices that measure the temperature changes caused by the absorption of this radiation are termed bolometer. There are semiconductor photosensitive devices based on materials such as mercury cadmium telluride that works as infra-red photodiode. Devices that produce an image out of an array of bolometer or photodiodes are termed as thermal imagers.

Over all, this talk will have a brief introduction to infrared detectors followed by the materials aspects and the choices available.  On met materials, another aspect of imaging infrared, will emphasize on the implications of vanadium dioxide in different infrared applications including microbolometers.  Finally, this will be followed by other prospective utilities of vanadium dioxide.

Wednesday, March 15, 2017