# Surface Plasmon Resonance Sensors Using Optical Vortices

## TL;DR

This paper explores how using optical vortices instead of plane waves in SPR sensors affects sensor performance and molecule manipulation.

## Contribution

The study introduces the use of optical vortices in SPR sensors and shows their potential for molecule manipulation without affecting detection performance.

## Key findings

- Using optical vortices does not significantly affect SPR sensor detection performance.
- Optical vortices can aid in positioning and manipulating molecules on the sensor surface.
- The first-order approximation of the Fresnel reflection coefficient was used in the analysis.

## Abstract

This study investigates the change in both the angular position and width of the reflectance minimum of an SPR sensor in the Kretschmann configuration when optical vortices instead of plane waves are used for illumination. An analytical expression of the reflectance is obtained for incident Laguerre–Gaussian beams, considering only the first-order approximation of the Fresnel reflection coefficient in a Taylor series. Numerical simulations reveal that the detection performance of SPR sensors is practically unaffected if optical vortices of this type are used as sources, even if the topological charges of the vortices are quite large. On the other hand, the use of optical vortices in SPR sensors could be very advantageous for positioning and manipulating analyte molecules on the surface of the sensor.