Theoretical Expression for the Noise Equivalent Power of Pyroelectric Detectors

Abstract

Absolute response and noise equivalent power of cyclotron resonanceassisted InSb detectors at submillimeter wavelengths An equivalent circuit appropriate for pyroelectric materials is derived without assuming a unidirectional pobi.rization 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 F p= p/[Cpp(,/ tan6)lJ. It is shown that the resulting expression for NEP is consistent with experimental results as measured in this laboratory.T HE use of the pyroelectric effect in detecting electromagnetic radiation l -S and in the measurement of heat transfer9-12 is of increasing popUlarity. For this reason, ids timely to publish a careful theoretical treatment of pyroelectric sensors which leads to an equivalent circuit and to equations giving the noise equivalent power (NEP) and specific detectivity (D*) which have proved quite fruitful in this laboratory.

Pyroelectric current measurements on PbZr0.2Ti0.8O3 epitaxial layers

“…The pyroelectric layer is modeled as a current source in parallel with a dielectric, which is a resistor and capacitor in parallel. 29,30 The SiO 2 passivation layer is represented by an equivalent resistance and capacitance. The pyroelectric current, i p,2x , is evaluated from the measured 2x current, i 2x , as…”