Upconversion signals in the wavelength region 407–550 nm were emitted from CaF<sub>2</sub>:Eu<sup>3+</sup> under 578.7 (or 589.2-) nm dye-laser excitation. The intensities of the upconversion signals were enhanced 25× under double-resonance excitation by a 589.2-nm dye laser and a 703.6-nm Ti:sapphire laser. Excited-state absorption cross sections were estimated for some of the transitions.
© 2001 Optical Society of America
(160.5690) Materials : Rare-earth-doped materials
(190.4180) Nonlinear optics : Multiphoton processes
(190.4400) Nonlinear optics : Nonlinear optics, materials
(190.7220) Nonlinear optics : Upconversion
(300.6360) Spectroscopy : Spectroscopy, laser
Wenyan Tian, Ranjit S. Pandher, and B. Rami Reddy, "Efficient infrared quantum counter and excited-state absorption cross-section measurements in europium-doped calcium fluoride," J. Opt. Soc. Am. B 18, 1627-1631 (2001)