OPTICAL DETECTORS USING NULLING FOR HIGH LINEARITY AND LARGE DYNAMIC RANGE

摘要

An infrared radiation detector includes a bolometer or micro-cantilever detector device which functions as a null detector in conjunction with electronic circuitry. The electronic circuitry senses a change in an output signal of the detector as the detector responds to infrared radiation incident upon the detector and provides a signal to a control element which provides a stimulus to the detector device to maintain the detector output signal at the same level. The element may be a piezoelectric element, a heater or a pair of electrodes and the corresponding stimulus may be stress, heat, or electrostatic change. The stimulus compensates for the effect of the infrared radiation and maintains the chosen detector output level at the same level. The nulling circuitry improves the linearity and dynamic range of the detector device.