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 a pyroelectric detector. The frequency-dependent current and voltage responsivities are explained. Factors influencing the choice of pyroelectric material for various applications are summarized. The possibilities of various new applications and the developments of pyroelectric detectors are discussed. A laboratory prototype demonstration system has been built using an ELTEC detector type 5192. For a high signal-to-noise ratio, an electric charge integration technique is applied. High-precision operational amplifiers are used for high-quality signal conditioning. The pyroelectric detector consists of two parallel opposed dual lithium tantalate pyroelectric single crystals with a junction FET source follower sealed in a standard TO-5 housing