Comparative study on diode-pumped continuous wave laser at 607  nm using differently doped Pr(3+):LiYF(4) crystals...

We comparatively study an InGaN laser-diode-pumped continuous-wave laser at ∼607  nm (σ polarization) using differently doped Pr:LiYF₄ single crystals. Maximum output power and slope efficiency at this wavelength were up to 209 mW and 47.1%, respectively, using a 0.2 at. % doped and 8 mm sample. Findlay-Clay analysis shows roundtrip losses, including reabsorption loss at this particular emission of about 1.2% using the 0.2 at. % doped sample, which is lower than that of samples with higher doping concentrations at 0.5 and 1 at. %. Using a 0.15 mm glass plate as a Fabry-Perot etalon, a maximum output power of 73 mW was achieved at ∼604  nm (π polarization) with slope efficiency of 17.2% for what is believed to be the highest result currently.