A metal-insulator-metal waveguide-based plasmonic refractive index sensor for the detection of nanoplastics in water.

A metal-insulator-metal waveguide-based square-ring resonator plasmonic refractive index sensor is designed and optimized for achieving high sensitivity. The sensitivity of the sensor critically depends on the physical dimension and the geometrical parameters of the resonator. Systematic studies on varying geometrical parameters of the resonator reveal that the sensitivity increases with the number of concentric square-rings.

Spin-Direction-Spin Coupling of Quasiguided Modes in Plasmonic Crystals.

We report an unusual spin-direction-spin coupling phenomenon of light using the leaky quasiguided modes of a waveguided plasmonic crystal. This is demonstrated as simultaneous input spin-dependent directional guiding of waves (spin-direction coupling) and wave-vector-dependent spin acquisition (direction-spin coupling) of the scattered light. These effects, manifested as the forward and the inverse spin Hall effect of light in the far field, and other accompanying spin-orbit interaction effects are observed and analyzed using a momentum (k) domain polarization Mueller matrix.

Natural weak value amplification in Fano resonance and giant Faraday rotation in magneto-plasmonic crystal.

The extraordinary concept of weak value amplification can be formulated within the realm of wave interference as nearly destructive interference between the eigenstates of the measuring observable. Here we report on a phenomenon of interferometric weak value amplification of small polarization rotation in Fano resonance that evolves completely naturally due to near destructive spectral domain interference between a continuum and a narrow resonance mode having slightly different polarization response. In order to elucidate this, we first experimentally demonstrate an interferometric weak value amplification concept by generating nearly destructive interference of two paths of an interferometer having slightly rotated linear polarization states of light.