A new method for detection of continuous infrared radiation by pyroelectric detectors

A novel method for detection of continuous infrared (IR) radiation by pyroelectric detectors was presented. In this method, instead of conventional modulation of IR radiation by mechanical parts, which are complicated and unreliable, the temperature of the detector is modulated by thermoelectric cooler to activate it. With this new method, the main inherent limitation for application of these detectors is expected to be eliminated. An equivalent electrical circuit was proposed to simulate the thermal and electrical behavior of the detector. A prototype sensor was fabricated and its transient responses to different level of IR radiations were recorded. The model-based calculations were fitted to the measured data, and the fitting parameters were considered as model parameters. Good agreement between experimental data and analytical calculations confirmed the validity of the model. It was also demonstrated that, the application of this method increases the detection speed of the sensor. Improved speed is more than three orders of magnitude better than the other type of thermal detectors.