Efficient Continuous Wave-laser emission of Pr3+-doped fluorides at room temperature

We report, to our knowledge for the first time, Continuous Wave (CW) laser emission at room temperature of Pr:LiYF4 (Pr.YLF) at six wavelengths: 522, 545, 607, 639.5, 720 and 907.4 nm. The pump source was an argon-ion laser tuned to a wavelength of ⋋ = 457.9 nm. The maximum output powers at 522 nm (3Pi →3H5) and 639.5 nm (3P0 →3F2) were 144 and 266 mW, respectively. We also observed CW laser action of Pr:GdLiF4 (Pr: GLF) at λ = 639 nm and of Pr:KYF4 (Pr: KYF) at λ = 642.5 nm.