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.
Pyroelectric crystals generate positive and negative charge carriers simultaneously on opposing sides. The LD21xx series is the first series in which both crystal sides are amplified separately.
Due to the separate amplification, the signals add up linearly (i.e., they are doubled). The noise components only add up statistically; therefore, there is a net gain in the signal-to-noise ratio!
Compared to the bestseller L2100 series, we were able to double the signal of the new LD21xx series. At the same time, the noise was kept almost consistently low. Our R&D team has taken out the bag of tricks and optimized the components used accordingly. The actual improvement in the signal-to-noise ratio is therefore significantly higher than the purely theoretical value of 1.4.
There are two basic options:
In the LD2100, the two amplified signals are put out separately (i.e., the detector has a real differential output, which also makes differential signal routing possible): Any external interference signals that are picked up are eliminated by differential formation. In addition, the LD2100 series allows simple wiring in which the signal outputs are fed directly to the inputs of a differential A/D converter.
In the LD2120, the differential formation is also integrated in the detector housing (i.e., this version is pin-compatible with traditional standard detectors such as the L2100).