Thermal Detectors: Understanding Bolometers and Their Applications

This lecture focuses on bolometers as thermal detectors, explaining their operational principles and applications. The instructor describes the structure of a bolometer, which includes a thermistor as an active element and a reference thermistor that is shielded from infrared radiation. The lecture details how temperature changes affect resistance, highlighting the generation of charge carriers and the impact of impurity and phonon scattering in semiconductors and metals. The construction of microbolometer arrays based on vanadium oxide is discussed, including their integration on wafers and the use of CMOS electronics for readout. The instructor explains the electronic interface for microbolometers, emphasizing the importance of voltage dividers and the selection of rows and columns for camera applications. The lecture concludes with a discussion of commercial microbolometer cameras, their resolution, and various applications, such as monitoring electronic contacts, motors, and body temperatures.