Pyroelectric detectors and their applications

The authors review the principles of operation of pyroelectric detectors. The equations for current responsivity, voltage responsivity, noise, noise equivalent power, and detectivity are derived from the fundamental thermodynamic model of the detector. Frequency-dependent current and voltage responsivities are explained. Factors influencing the choice of pyroelectric material for various applications are briefly summarized. Various possible new applications and developments of pyroelectric detectors are briefly mentioned. A laboratory prototype demonstration system has been built. An electric charge integration technique has been used to obtain high signal-to-noise ratio. A high-precision operational amplifier has been used for high-quality signal conditioning. The pyroelectric detector used consists of two parallel opposed lithium tantalate pyroelectric single crystals with a JFET (junction field-effect transistor) source follower sealed in a standard TO-5 housing.<>