Figure 2. Excitation enhancement upconversion process with ESA mechanism for GNR.

(a) The fourth power of local E-field–induced ESA factor (red) and relaxation factor (black) as a function of separation for GNR (squares) and GNP (circles). (b) Excitation enhancement as a function of separation for GNR (red squares) and GNP (black dots). The calculation of excitation is performed at wavelength of 980 nm under the configuration in Fig. 1b with dipole emitter located at position A.