Theoretical Expression for the Noise Equivalent Power of Pyroelectric Detectors

Abstract

An equivalent circuit appropriate for pyroelectric materials is derived without assuming a unidirectional polarization vector. This circuit is used to obtain a theoretical expression for the noise equivalent power (NEP) for detectors using pyroelectric sensing elements. It is found that a good figure of merit for pyroelectric materials is given by Fp=p/[Cpρ(εr′ tanδ)½]. It is shown that the resulting expression for NEP is consistent with experimental results as measured in this laboratory.