Polarized, broadly tunable, 2.3 µm continuous-wave laser operation of Tm3+-vanadate crystals

Abstract

We report for the first time the polarized, broadly tunable, continuous-wave laser operation on the 3H4 → 3H5 transition in Tm3+-vanadate (Tm:REVO4, RE = Gd, Y, Lu) crystals. Continuous wavelength tunings with tuning widths of about 200 nm were achieved in π-polarization for both the Tm:GdVO4 and Tm:YVO4 crystals. To the best of our knowledge, these tuning widths are broader than most previously reported values for wavelength tunable 2.3 µm Tm lasers. Especially for σ-polarization, all the Tm:REVO4 lasers provide very smooth wavelength tuning curves around 2.3 µm. This work demonstrates the excellent broad wavelength tunability of the Tm:REVO4 crystals and their great potential for supporting the generation of ultrashort pulses from mode-locked lasers.