Minimum Detectable Power of a Pyroelectric Thermal Receiver

Abstract

For a ferroelectric crystal, the rate of change of polarization with temperature is large, especially close to the Curie point where a phase transition occurs. Thus, a change of polarization due to an incident radiation flux gives rise to a large pyroelectric voltage output. The ``minimum detectable power'' W_m is calculated. For barium titanate, the value of W_m thus obtained is found to be much better than other uncooled thermal receivers and comparable with a superconducting bolometer, if dielectric noise at the transition is small. In certain cases, W_m is limited only by temperature noise, so that the receiver may be thought of as a true thermal receiver.