# Summary of optical spectroscopy methods The choice of an optical spectroscopy technique, the measurement setup and the recording of the spectra must be carefully considered, and the following overviews are intended to provide an initial starting point.
**Electron excitation** | **Vibrational spectroscopy** | ||||
**UV/VIS** | **Fluorescence** | **NIR** | **MIR** | **RAMAN** | |
**Signal** | Absorption | Emission | Absorption | Absorption | Scattering |
**Excitation** | Halogen, Deuterium (UV) | Discharge lamp, Laser | Halogen | Thermal emitter | Laser |
**Detector** | Si | Si | InGaAs MCT | MCT | Si InGaAs |
**Sensitivity** | high | high | mid | high | mid |
**Specifics** | - | Detector 90° in direction of excitation | - | Special optical materials | longpass filter for excitation blocking |
**Imaging** | simple | higher effort | simple | high effort | higher effort |