Application Laboratory μSpectrum
Raman spectroscopy


Spectroscopic methods such as Raman spectroscopy can be used to precisely analyse mixtures of substances and detect a wide variety of substances – thanks to a signature that is as typical as a fingerprint. However, these Raman signals are relatively weak.

With Shifted Excitation Raman Difference Spectroscopy (SERDS), however, interferences caused by background light or fluorescence of the examined sample can be separated from the Raman signatures.


Laser light sources suitable for SERDS provide two slightly spectrally shifted excitation wavelengths. For example, they use GaN-based diode lasers in external resonators or the frequency doubling of a GaAs-based two-wavelength laser diode. If the excitation wavelength of the laser is also in the spectral vicinity of an absorption, the Raman signal can be amplified. This allows it to be used for so-called resonance Raman spectroscopy.

SERDS is used in a variety of ways, including measuring selected target substances on human skin, in apples or on soil samples.

More information on the FBH website.


Recording of weak Raman signals

Measurements under real conditions

Spectrometerless measurements possible

Measurements in liquid, on skin and on soil samples possible


Medical diagnostics / life science


First applications under real conditions;
Further development into a spectrometerless Raman measurement system


PD Dr. Bernd Sumpf

Leibniz-Institute for High Frequency Technology

Gustav-Kirchhoff-Str. 4
12489 Berlin

T:  +49 (0)30 6392 2659