The basic material of pyroelectric detectors with the highest performance level is DLaTGS (i.e., deuterated and L-alanine-doped triglycine sulfate). The D* of DLaTGS is typically 2.5 times higher than in LiTaO3 detectors. DLaTGS detectors have a high detectivity, even at high frequencies, and a wide spectral sensitivity range from UV to THz wavelengths that is only limited by the detector window used. The Curie temperature of DLaTGS is 61°C and thus more than 10 K higher than TGS (triglycine sulfate).
This is achieved by the process of deuteration, the complete replacement of all hydrogen atoms by deuterium atoms.
Additional doping with L-alanine increases the sensitivity of detectors and prevents permanent depolarization when heating beyond the Curie temperature.
Currently, there are four different detector series available that are used in various applications. The LCDT-5000 series is directed at users who would like to combine their detectors with their own electronics (external FET for voltage mode or low-noise operational amplifiers for current mode). The LCDT-5100 series is designed for low-frequency applications in the range of 10…100 Hz and utilizes an integrated JFET with an extremely low leakage current and a high ohm resistor. The LCDT-5500 series is equipped with a low-noise JFET and a high D* and designed for FTIR applications. The LCDT-5500CM series detectors are equipped with an integrated operational amplifier, operate in current mode, and are the best choice for FTIR applications in the frequency range of 1…4 kHz – for which a large output signal and a high noise-to-signal ratio are required.
All detectors have in common that they possess thinned-out elements and optionally feature a special absorbing black coating with a low thermal mass that offers a wide spectral response at a simultaneously high speed.
All detectors are not only available with different diameters of their active surfaces (e.g., 1.0 mm, 1.3 mm, 2.0 mm, or 3.0 mm) but rectangular and square shapes as well. Standard housings include, for example, TO-5, TO-66, and TO-37.
