Fourier-transformed IR spectroscopy (FTIR) requires particularly sensitive detectors. At low to medium modulation frequencies, special pyroelectric LTO detectors are 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, specific detectivity is 4.0 E+09 Jones. The LT3111 detectors perform similarly to more expensive thermoelectrically cooled semiconductor detectors.
For pyroelectric detectors, the general rule is thinner chips supply higher detectivity. We use chips with a thickness of 7 µm. LTO chips are extremely robust and supply consistent temperature stability. While other detector types in industrial environments require a Peltier element, LTO technology works well at elevated temperatures without the need for added cooling.
