InGaN-LD-pumped Pr3+:LiYF4 continuous-wave deep red lasers at 697.6 and 695.8 nm

We report a power-scaled operation at pi-polarized similar to 698 nm and sigma-polarized similar to 696 nm deep red lasers in Pr:YLF crystal pumped by a 2-W InGaN LD (laser diode) after a pump beam reshaping. The maximum output power of the pi-polarized laser emission at 697.6 nm was up to 348 mW with slope efficiency of about 32.7% in a free-running mode. The sigma-polarized laser emission at 695.8 nm was also realized for the first time using a simple and compact Brewster-angle orientated intracavity etalon playing role as birefringence filter and the generated maximum output power of the 695.8 nm laser was up to 116 mW with slope efficiency of about 18.5% with respect to the absorbed pump power. (C) 2014 Elsevier Ltd. All rights reserved.