Surface plasmon based sensing with broadband coherent laser pulses

TL;DR

This paper presents a novel broadband coherent laser pulse method for surface plasmon resonance sensing, enabling efficient detection of refractive index changes through spectral and angular shifts, with a versatile multilayer model.

Contribution

It introduces a new broadband coherent laser pulse technique for SPR sensing and a comprehensive multilayer model for simulating complex sensor configurations.

Findings

Efficient detection of refractive index changes via spectral and angular shifts.

The model accounts for multiple layers and functionalizing layers.

Enhanced sensitivity through combined intensity and phase measurements.

Abstract

A broadband detection method with coherent laser pulses exciting surface plasmons is investigated. The intensity and phase characteristics of the reflected light in Kretschmann configuration are calculated. It is shown that by mixing in-plane and out-of-plain polarization components of the incident light, the measurements of the changes of the refractive index of the adjacent media can be efficiently performed by observing the shift of the steep slope of the surface plasmon resonance (SPR) reflectance curve. We have demonstrated that such sensing can be performed by observing the angular shift of the SPR curve as well as the spectral shift. The developed model can account for an arbitrary number of layers and is used to simulate the response when an additional functionalizing layer adjacent to the gold film is used.