Sculpting nanometer-sized light landscape with plasmonic nanocolumns

Abstract

Plasmonic structures are commonly used to both confine and enhance surface electromagnetic fields. In the past ten years, their peculiar optical properties have given rise to many promising applications ranging from high density data storage to surface optical trapping. In this context, we investigated both far-field and near-field optical response of a collection of densely packed silver nanocolumns embedded in amorphous aluminum oxide using the discrete dipole approximation. In the far field, a good fit of the calculated to the experimental absorption spectra can only be achieved when in addition to interaction between neighboring nanocolumns, a nanorod shape with periodic shrinks mimicking the experimental morphology of the nanocolumns is used. In the near field, modulated field intensities following the nanocolumns distribution and tunable with the incident wavelength are predicted outside the region occupied by the nanocolumns. This plasmonic image transfer has a resolution of approximately 1.8D where D is the diameter of the nanocolumns that in our case is 2.4 nm.

Unusual resonances in nanoplasmonic structures due to nonlocal response

“…Resolving this issue is important for the engineering of ultrasmall plasmonic structures with optimized functionalities. [19][20][21] In this Rapid Communication we report that unusual resonances due to nonlocal response do exist in nanoplasmonic structures, but only above the plasma frequency, not in the visible. We illustrate this property of arbitrary plasmonic structures by exact calculations for metallic cylinders.…”

“…15 Importantly, additional resonances of the free-electron plasma were found, also at optical frequencies, which have no counterparts in local-response theories. Such resonances have already gained interest both from a fundamental 7 and an applied 19 perspective. At present, the status of these optical nonlocal resonances is unclear, since in Ref.…”

Effect of non-pore-widening on plasmon resonances of silver nanowire arrays in Anodized Aluminum Oxide

“…Studies about geometry of single nanowire's influence on plasmon resonances are not available before, which will be studied in this Letter [15].…”

Determination of Morphological Parameters of Supported Gold Nanoparticles: Comparison of AFM Combined with Optical Spectroscopy and Theoretical Modeling versus TEM

“…One direct and powerful technique is transition electron microscopy (TEM) [15,[28][29][30][31][32][33][34][35][36][37]40], but TEM suffers from the fact that sample preparation for three-dimensional TEM investigations is rather complicated and cannot be easily accomplished in situ. In addition, obtaining sufficient statistical data from TEM measurements is extremely time consuming.…”

“…Different techniques are employed to characterize the particle morphology [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39].…”