Direct characterization of planar waveguide modes by Fourier plane fluorescence leakage radiation microscopy

TL;DR

This paper introduces a fluorescence leakage radiation microscopy technique to directly and efficiently characterize multiple modes in planar waveguides by analyzing their Fourier plane images, validated through experiments and simulations.

Contribution

It extends leakage radiation microscopy to planar waveguide mode characterization, enabling rapid, simultaneous measurement of propagation constants.

Findings

Propagation constants of multiple waveguide modes can be quickly derived.

Experimental results agree with numerical simulations.

The method offers a simple, high-efficiency way to characterize planar waveguides.

Abstract

In this letter, the leakage radiation microscopy (LRM) is extended into characterization of planar waveguide modes (WMs) rather than surface plasmon polaritons (SPPs) taking advantages of the coupling between WMs and fluorescence emission. Propagation constants of different WMs allowed in the same planar waveguide can be simultaneously and rapidly derived from the Fourier plane image of fluorescence based LRM. Numerical simulations are also carried out to calculate propagation constants of these modes, which are consistent with experimental results. Our experiments provide a simple but high efficient method to characterize planar waveguides.