Correlation of circular differential optical absorption with geometric chirality in plasmonic meta-atoms

Abstract

We report a strong correlation between the calculated broadband circular differential optical absorption (CDOA) and the geometric chirality of plasmonic meta-atoms with twodimensional chirality. We investigate this correlation using three common gold meta-atom geometries: L-shapes, triangles, and nanorod dimers, over a broad range of geometric parameters. We show that this correlation holds for both contiguous plasmonic meta-atoms and non-contiguous structures which support plasmonic coupling effects. A potential application for this correlation is the rapid optimization of plasmonic nanostructure for maximum broadband CDOA.

Mueller matrix polarimetry of bianisotropic materials [Invited]

“…A similar response was found for oblique arrays of perforated holes in gold [30]. At normal incidence, however, magnetoelectric coupling effects cannot be excited for strictly planar systems, albeit it is still possible to have phenomena such as asymmetric transmission of CPL [30,89]. This is shown in Fig.…”

Understanding Artifacts in Chiroptical Spectroscopy

“…We have focused here on ROA, but these same principles can be applied to other chiroptical measurement techniques such as CD and VCD. Matrices for CD and VCD have already been reported in the literature. , Similarly, these matrices can be used to understand how artifacts impact CD and VCD spectra. Unlike ROA and other scattering or two-photon chiroptical techniques, CD and VCD are only dependent on the polarization purity of the incident light.…”

“…However, both CD and VCD are also sensitive to linear and circular birefringence and effects of dichroism in the sample. This can also lead to mirror-image spectra that are not the result of chiral phenomena . The spectral characteristics of artifacts outlined above are all valid for CD and VCD measurements, and the second and third of our suggested controls are also relevant for absorptive chiroptical techniques such as CD and VCD.…”

“…However, such measurements are still prone to artifacts . Signals can arise that are easily confused with chiral effects . Unfortunately, while papers on chiroptical spectroscopy often mention the problem of artifacts, very few offer thorough descriptions of artifact spectra.…”

“…10 Signals can arise that are easily confused with chiral effects. 11 Unfortunately, while papers on chiroptical spectroscopy often mention the problem of artifacts, very few offer thorough descriptions of artifact spectra. Moreover, a standard set of control measurements has not been accepted by the community.…”