title: Optimization and maximum potential of optical antennae in near-field enhancement.
abstract: We investigate four types of gold nanoantennae (the monopole, the dipole, the cone-shaped, and the cone-bowtie antenna), under a fixed working wavelength. The finite-difference time-domain (FDTD) simulations show that the near-field enhancement values do not increase monotonously when the antennae sizes decrease, and optimization conditions vary with the antenna shapes. We also propose a distributed dipole ring model to analytically calculate the near field. The size condition for the strongest enhancement is the compromising result of the total radiated energy and the near-field distribution factor. Assuming the cone-bowtie antenna is the best for high enhancement, the maximum potential in near-field enhancement is 2×10(5) for a linear signal or 4×10(10) for typical nonlinear signals.
authors.forename: PingPing
authors.initials: P
authors.lastname: Chen
authors.forename: Ju
authors.initials: J
authors.lastname: Liu
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Kuijuan
authors.initials: K
authors.lastname: Jin
authors.forename: Yan
authors.initials: Y
authors.lastname: Yin
authors.forename: ZhiYuan
authors.initials: Z
authors.lastname: Li