Fourier-transformed IR spectroscopy (FTIR) requires particularly sensitive detectors. At low to medium modulation frequencies, special pyroelectric LTO detectors are very well suited for this purpose. LASER COMPONENTS’ LT3111 series pyroelectric detectors offer high detectivity and a good signal-to-noise ratio at low modulation frequencies. At 10 Hz the specific detectivity is typically 4.0 E+09 Jones. As a result, the LT3111 detectors perform similarly to the more expensive thermoelectrically cooled semiconductor detectors.
For pyroelectric detectors, the basic rule is that thinner chips provide higher detectivity. In this case, we use chips with a thickness of 7 µm. LTO chips are extremely robust and above all temperature stable. While other detector types in industrial environments require a Peltier element, LTO technology works well even at high temperatures without additional cooling.