Detectors with sensitivity to wavelengths above 1 um. Careful selection of material combinations allows offering a variety of types that cover a broad spectral range.
InGaAs photodiodes are sensitive to wavelengths over a wide range. These are available as image sensors, linear arrays, and photodiode/amplifier devices, etc.
Photoconductive detectors whose resistance drops when exposed to infrared light. PbS is sensitive to wavelengths from 1 to 3.2 um, and PbSe from 1.5 to 5.2 um.
MCT detectors are available in two operating types: a photoconductive type that lowers resistance by input of infrared light and a photovoltaic type having a PN junction.
Two-color detectors incorporate an infrared-transmitting Si photodiode mounted over a PbS detector, PbSe detector or InGaAs PIN photodiode along the same optical axis.
