Response of a Triglycine Sulphate Pyroelectric Detector to High Frequencies (300 kHz)

Abstract

The theory and performance of two types of pyroelectric TGS detectors working at room temperature, one type having electrodes on the front and back surfaces of the crystal plate and the other type with electrodes on the two-side surfaces, have been investigated. They have the same signal-to-noise (S/N) ratio at high frequencies, but the second type detectors, when used with a high-bias resistor, give a higher signal if they have a long edge parallel to the pyroelectric axis. One TGS detector, modified to give a bandwidth of 100 kHz was compared to a gold-doped germanium detector using a CO2 laser as the source. The S/N ratio of the TGS detector is nearly ⅕ of the germanium detector. The type II detector has also been used to study a HCN laser pulse. The possibilities of pyroelectric detectors working at room temperature appears promising in spite of their intrinsic character of thermal detectors.