# Design, Fabrication and 3D Volumetric Characterization Criteria for Plasmonic Bullseye Structures

## TL;DR

This paper investigates design criteria and characterization techniques for plasmonic bullseye structures, proposing an optimized design for enhanced far-field intensity and evaluating a 3D confocal microscopy method for device characterization.

## Contribution

It introduces a new optimized bullseye structure for improved collimated emission and compares it to existing designs, while also proposing and experimentally validating a 3D confocal microscopy characterization method.

## Key findings

- Optimized bullseye design achieves higher far-field intensity.
- 3D confocal microscopy effectively characterizes device focal points.
- Matching grating periodicity to surface wave wavelength enhances collimation.

## Abstract

In this report, certain claims regarding the design criteria and characterizations of plasmonic bullseye (BE) structures are investigated. Does the matching of the grating's periodicity to the wavelength of surface waves results in a strong collimated beam along the optical axis of the device? What are the requirements for such devices if they are set to enhance the radiative decay rate of a quantum emitter? These questions are answered by proposing and modelling a new bullseye structure, optimized based on maximization of the far-field intensity along the optical axis. Dimensions and the performance of the proposed BE are then compared to that reported by another author. The other question to be answered is the characterizations techniques. What is the best approach in characterizing such devices? How many focal points are there along the optical axis? What are the strengths and depths of focus at each point? How collimated is the output beam? Techniques proposed by other authors are debated and a technique based on 3D confocal microscopy is proposed and applied experimentally to the alternative proposed device.

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Source: https://tomesphere.com/paper/1906.00200