Angular momentum-induced circular dichroism in non-chiral nanostructures

Abstract

Circular dichroism (CD), i.e. the differential response of a system to left and right circularly polarized light, is one of the only techniques capable of providing morphological information of certain samples. In biology, for instance, CD spectroscopy is widely used to study the structure of proteins. More recently, it has also been used to characterize metamaterials and plasmonic structures. Typically, CD can only be observed in chiral objects. Here, we present experimental results showing that a non-chiral sample such as a sub-wavelength circular nano-aperture can produce giant CD when a vortex beam is used to excite it. These measurements can be understood by studying the symmetries of the sample and the total angular momentum that vortex beams carry. Our results show that CD can provide a wealth of information about the sample when combined with the control of the total angular momentum of the input field.

References in corpus (3)

• Observation of the spin-based plasmonic effect in nanoscale structures
• Circular dichroism of cholesteric polymers and the orbital angular momentum of light
• Excitation of single multipolar modes with engineered cylindrically symmetric fields

Cited by in corpus (15)

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• When does nonlinear circular dichroism appear in achiral dielectric nanoparticles?
• Mimicking Chiral Light-Matter Interaction
• Non-zero helicity extinction in light scattered from achiral (or chiral) small particles located at points of null incident helicity density
• Chiral discrimination by polarization singularities of a metal sphere
• Symmetry-protection of multiphoton states of light
• Spin-orbit interactions of the twisted random light
• Dichroism for Orbital Angular Momentum using Stimulated Parametric Down Conversion
• Achiral nanostructures: perturbative harmonic generation and dichroism under vortex and vector beams illumination
• Coherent control of optical spin-to-orbital angular momentum conversion in metasurface
• Three-dimensional chiral microstructures fabricated by structured optical vortices in isotropic material
• Chiral light by symmetric optical antennas