Photon counting modules, for example, are suited for applications with a particularly low light level. Spectrally speaking, our product range is designed mainly for the NIR and IR ranges. In highly simplified terms, you could say that the NIR range is less specific because the harmonics of the molecules are analyzed. Sample preparation, on the other hand, is easy and the detectors, emitters, and accessories are of a highly technological standard, just as those used in telecommunication applications. The IR range offers access to basic oscillations; however, the sample preparation (of solids and liquids) is more complex. Broadband methods in which wavelength-selecting elements, for example, a Michelson interferometer (a method known as FTIR) or a Fabry Perot interferometer (FPI) are used are universally applicable in the IR range. So-called NDIR spectrometers or photometers are widely used in quantitative analysis. Optical filters are used as selecting elements here. NDIR devices are usually designed for use with one or multiple very specific analytes.

Another variation is tunable diode laser absorption spectroscopy (TDLAS), in which the light source is narrow banded and can be electrically tuned.

Nonlinear methods of optical spectroscopy, such as Raman spectroscopy in particular, are being used more and more. Due to nonlinear processes, a so-called Raman spectrum is produced, today generally with the help of a laser, and then analyzed using a conventional spectrometer.