Tb:YLF laser at 412.7 nm and 435.1 nm

Solid-state lasers in the violet and blue spectral range are an indispensable tool in industry and research. Currently, these mainly rely on complex and bulky frequency-conversion schemes. This is due to a lack of sources with direct emission in this wavelength range. Here, we report on the first, to our knowledge, direct laser emission, at 412.7 nm and 435.1 nm from the 5 D 3 multiplet in Tb 3+ :LiYF 4 . At a temperature of 78 K, continuous-wave pumping at 376 nm enables slope efficiencies of up to 35% and a maximum output power of 150 mW at 412.7 nm and 20 mW output power at 17% slope efficiency at 435.1 nm. These efficiencies are higher than all other values previously achieved with solid-state lasers in the sub-450 nm range and surpass these by an order magnitude in terms of output power.