Visible Discrimination of Broadband Infrared Light by Dye-Enhanced Upconversion in Lanthanide-Doped Nanocrystals

Figure 9

Power dependence of direct atomically excited upconversion of NaYF₄:Yb³⁺, Ho³⁺ excited at 975 nm (a). Beam size measurement of the fiber-coupled 975 nm diode laser (b). Power dependence of direct atomically excited upconversion of NaY_0.85Er_0.15F₄ excited at 801 nm (c). Beam size measurements for the vertical and horizontal directions for the 801 nm free-space diode laser (d).

(a)

(b)

(c)

(d)