Upconversion photon quantification of Ho3+ in highly transparent fluorotellurite glasses

Abstract Multi-photon-excited green, red and oxblood UC emissions have been quantified in highly transparent Ho 3+ /Yb 3+ doped fluorotellurite (BALMT) glasses under the excitation of 977 nm laser. The net powers of green, red and oxblood emissions are determined to be 88.1, 103.8 and 66.1 μW in 0.196% Ho 2 O 3 and 0.752% Yb 2 O 3 co-doping case under the excitation power of 870 mW, and the net emission photon numbers are identified to be 242.7 × 10 12 , 342.8 × 10 12 and 250.8 × 10 12  cps. The quantum yields (QYs) and luminous fluxes for visible UC emissions of Ho 3+ are identified as a positive dependency with pumping powers, and when the excitation power density increase to 110.8 W/mm 2 , the QY values for 550 nm green, 650 nm red and 753 nm oxblood UC emissions are up to 0.63 × 10 −4 , 0.90 × 10 −4 and 0.65 × 10 −4 , respectively. The values of QY in Ho 3+ doped BALMT glass are one order of magnitude larger than that in NMAG glasses. The macroscopic quantization for UC photon generation from Ho 3+ in low-phonon fluorotellurite glasses provides a reliable reference for developing compact high-power-density illuminant for remote sensing, radar detection and medical diagnosis.