Construction and testing of a tunable light source for characterisation of Silicon Photomultipliers

This thesis describes the development and construction of a tunable light source which shall be used as test stand for the photo detection efficiency of a silicon photomultiplier (SiPM). Tunable means that in the finished construction it is possible to select visible light of different wavelengths between 400 nm and 800 nm. The set-up has a main light source whose light is split by either a blazed grating or an equilateral prism, respectively. The spectral light is collected by an optical fibre and coupled into an integrating sphere which is a core element of the readout. In the actual set-up a PIN diode is integrated which later will be used as reference detector. This allows first measurements with the complete set-up. The SiPM to be tested also will be mounted at the integrating sphere. Later a reference light source with four defined wavelengths serves to calibrate the set-up. First measurements of the photo detection efficiency using the PIN diode provide the expected wavelength spectrum.