Advanced spectral response measurement with wide range tunable laser system

The measurement uncertainty in a production line depends on the reference cell uncertainty and has a high economic impact. Therefore, there is a steady development in calibration setups and procedures aiming for a further reduction of measurement uncertainty. At the Fraunhofer ISE CalLab PV Cells we develop a new, highly sophisticated spectral response measurement facility based on wide-range tunable ultrashort laser pulses that will improve our calibration chain and supply references with lower measurement uncertainty. In this paper we present our development of this new setup and discuss our approaches to tackle the specific requirements arising from the special characteristics of ultrashort pulses regarding their applicability in spectral response measurements. We demonstrate the functionality of our new Laser-DSR setup by showing first results and comparing them to state-of the- art calibration setups. Further, we exemplify the advantages of the gap-free wavelength tuning by a temperature coefficient measurement of CdTe. Finally, we discuss the expected improvements in measurement uncertainty and conclude the current status of our setup development.