title: Focusing dual-wavelength surface plasmons to the same focal plane by a far-field plasmonic lens.
abstract: In this Letter, we demonstrate the nanoscale focusing of surface plasmons (SPs) at two different wavelengths to the same focal plane by a far-field plasmonic lens both numerically and experimentally. The far-field plasmonic lens, which consists of an annular slit and a concentric groove and is capable of focusing dual-wavelength SPs to the same focal plane, is characterized by a scanning near-field optical microscope under both linearly and radially polarized illuminations. The demonstrated far-field plasmonic lens can provide immense opportunities for on-chip photonic applications, including dual-wavelength-based super-resolution imaging and ultra-high-density optical data storage.
authors.forename: Priyamvada
authors.initials: P
authors.lastname: Venugopalan
authors.forename: Qiming
authors.initials: Q
authors.lastname: Zhang
authors.forename: Xiangping
authors.initials: X
authors.lastname: Li
authors.forename: L
authors.initials: L
authors.lastname: Kuipers
authors.forename: Min
authors.initials: M
authors.lastname: Gu