Investigation of blue emission from Raman-active crystals: Its origin and impact on laser performance

摘要

The origin and consequences to laser performance of blue emission observed in some Raman crystals has been studied in detail, leading us to attribute the origin of the phenomenon to fluorescence from Tm3+(1G4) impurity ions which are excited via sequential upconversion. For the specific case of a Nd:YLF/KGW Raman laser, we show that the blue fluorescence has modest but significant impacts on laser performance and thermal loading. If the blue fluorescence was eliminated, then laser efficiency could be increased by 15% and thermal loading in the KGW crystal reduced by 17%.