Diffraction grating revisited: a high-resolution plasmonic dispersive element

TL;DR

This paper introduces a novel plasmonic crystal that significantly enhances spectral dispersion, enabling high-resolution spectroscopy in compact, planar devices through surface plasmon polaritons and nanostructuring.

Contribution

The work demonstrates a new method to achieve ultra-high spectral dispersion using a finite-size SPP crystal, advancing the design of compact, high-resolution dispersive elements.

Findings

Achieved two orders of magnitude increase in spectral dispersion.

Demonstrated conversion of incident light to SPP Bloch waves on nanostructured surfaces.

Potential applications in high-resolution spectrographs and integrated photonic devices.

Abstract

The spectral dispersion of light is critical in applications ranging from spectroscopy to sensing and optical communication technologies. We demonstrate that ultra-high spectral dispersion can be achieved with a finite-size surface plasmon polaritonic (SPP) crystal. The 3D to 2D reduction in light diffraction dimensions due to interaction of light with collective electron modes in a metal is shown to increase the dispersion by some two orders of magnitude, due to a two-stage process: (i) conversion of the incident light to SPP Bloch waves on a nanostructured surface and (ii) Bloch waves traversing the SPP crystal boundary. This has potential for high-resolution spectrograph applications in photonics, optical communications and lab-on-a-chip, all within a planar device which is compact and easy to fabricate.