Development of a temperature control system for spectroscopic measurements with rare-earth doped crystals

Abstract: This thesis describes the development of a temperature control system for optical spectroscopy experiments with rare-earth doped samples. Low temperature emission spectra were afterwards recorded for a series for Eu3+ singly doped and Ce3+, Eu3+ codoped Y2SiO5 samples. The analysis and assignment of the different energy transitions is presented. The experimental setups used in this thesis involve the optics part, the electronic part and the cooling down system. For the optical measurements, two kinds of pumping laser were used: Dye laser (580 nm) and UV laser (370 nm). A suitable optics system was designed for the collection of fluorescence signals. Electronic circuits were on the other hand built to connect two thermal sensors within the cryostat used for the optical measurements. Two reference temperature sensors were set up so that they could be readout simultaneously by using a switch connected with a temperature monitor. A good control of the cooling down process and the final temperature reached by the samples under investigation is fundamental for spectroscopic investigations performed at cryogenic temperatures as the ones described here.