Diode-pumped violet energy upconversion in BaF_2:Er^3+

Abstract

Under 805-nm diode-laser excitation we detected intense upconversion signals at 410, 380, and 275 nm in BaF(2):Er(3+). Energy upconversion schemes and efficiencies are discussed in detail. Intensity parameters of Er(3+) in BaF(2) were derived as Omega(2) = 1.048 ? 0.117 x 10(-20) cm(2), Omega(4) = 1.478 ? 0.180 x 10(-20) cm(2), and Omega(6) = 1.009 ? 0.127 x 10(-20) cm(2).