Upconversion of Infrared Radiation in Er3+-Doped Alkaline-Earth Fluorides

摘要

Upconversion in MeF2-ErF3 (Me is Ca, Sr, or Ba) crystals with ErF3 concentrations from 0.01 to 10 mol % excited into the IR absorption bands of Er3+ by laser diodes at wavelengths of 808, 978, and 1542 nm is studied. In the case of excitation at lambda = 1542 nm, the dominant band in the MeF2-Er emission spectrum corresponds to the I-4(11/2)-I-4(15/2) transition at 990 nm, while the contribution of visible bands is less than 0.1. The upconversion luminescence energy yield of MeF2-10% ErF3 crystals excited by 1542-nm radiation with a power density of about 1 W/cm(2) varies from 14 to 26%.