Pyroelectric detectors are thermal detectors; i.e. they create an electric signal due to temperature changes in the chip. This temperature change is caused by absorption of light. We do use LiTaO3 and DLaTGS as pyroelectric materials. Basically such detectors cover the whole spectra. However, they are mainly used for mid-wave and long-wave infrared detection (MWIR and LWIR). In addition, the usage in the THz region seems to become more popular these days.
An IR filter makes all the difference. Thermal detectors are naturally polychromatic, and a filter is needed to detect specific gases/wavelengths.
Single wavelengths can only be detected if corresponding narrow-band filters are used because without the appropriate filter pyroelectric detectors would not even be able to detect a single gas.
The filters for pyroelectric detectors are not available individually but only in combination with our pyroelectric detectors on a standard basis. For purposes of development, however, we offer an optical gas and flame filter kit. This kit comprises 17 IR bandpass filters integrated in a socket for a TO-39 housing.
In the datasheet below, you will find the most current filters available for selection. If the appropriate filter for your application is not listed, please inquire with us.