Fig. 3: Photonic effects on upconversion (UC) as a function of the design wavelength λdesign.
From: Experimental validation of a modeling framework for upconversion enhancement in 1D-photonic crystals
a Average relative local density of optical states (\(\overline {{\mathrm{LDOS}}} _{{\mathrm{rel}}}\)) in the active layers of the Bragg structure for the main UC emission and main loss emission. b Average relative energy density (\(\bar u_{{\mathrm{rel}}}\)) in the active layers of the Bragg structure for an excitation at 1523 nm for an ideal Bragg structure and the fabricated structure including measured production inaccuracies. c–e Relative UC photoluminescence (UCPLrel) at 3 mW cm−2 (1 sun), as well as at 1.48 W cm−2 (~500 suns) irradiance as in experiment, only taking into account the LDOS effect (c), the effect of the relative energy density (d), and both effects (e). Under 1 sun illumination, the irradiance in the absorption range of the upconverter Er3+ (1450 nm–1600 nm) is 3 mW cm−2 (ref. 53).
