The above results further demonstrate that the controllability and robustness of these V-shaped structures are preserved for donor-acceptor pair with asymmetric configuration. Figure 5 The

see more nETR spectra for different V-shaped nanorods structures, with θ 1 = θ 2 = 60°, θ D = 60°, and θ A = 30°. (a) The nETR spectra for V-shaped structures shown in Figure 3a with different gap widths compared with the single nanorod structure. (b) The nETR spectra for V-shaped structures with a sharp corner part (black), cylinder corner part (red), or no corner part (green), g = 10 nm, and . The other parameters are L′ = 290 nm and d = 20 nm. Conclusions In summary, we have investigated the enhancement of the RET rate between donor and acceptor associated by the surface plasmons of the Ag nanorods on a SiO2 substrate. For donor-acceptor pair with parallel dipole moment directions, we have considered single nanorod with different cross sections, and the results revealed that the cylinder nanorod has the strongest ability to enhance the RET rate. We also found that the enhancement of RET rate in the single nanorod structure decreases for donor-acceptor pairs with nonparallel dipole moment directions. We then proposed simple V-shaped nanorod structures for nonparallel donor-acceptor pair. We

demonstrate that DNA Damage inhibitor the enhancement effect in these structures can be controlled by the nanorod length of the branch in the V-shaped structure. Our initial design of the V-shaped structure contains a corner part to improve the coupling between two nanorod branches, while we then find that the enhancement ability of the V-shaped structures is robust regardless of the shape and Epothilone B (EPO906, Patupilone) material of the corner part. Therefore, we may remove the corner part, and the V-shaped structure with two nanorod branches can lead to the remarkable RET rate enhancement that is ten times larger than that by the single nanorod. We also demonstrate that the controllability and robustness of these V-shaped structures are

preserved for donor-acceptor pair with asymmetric configuration. Our work provides guidance on the application of simple nanorod structures to improve RET efficiency in integrated photonic devices. Authors’ information YCY and JML are PhD students at Sun Yat-sen University. CJJ and XHW are professors of Sun Yat-sen University. Acknowledgments This work was financially supported by the National Basic Research Program of China (2010CB923200), the National Natural Science Foundation of China (grant U0934002), and the Ministry of Education of China (grant V200801). References 1. Barnes WL, Andrew P: Quantum optics: energy transfer under control. Nature 1999, 400:505–506.CrossRef 2. Andrew P, Barnes WL: Förster energy transfer in an optical microcavity. Science 2000, 290:785–788.