The optical properties of a ferrofluid in applied magnetic field: hyperbolic metamaterial

Author/Creator

Author/Creator ORCID

Date

2014-07-24

Department

Towson University. Department of Physics, Astronomy, and Geosciences

Program

Citation of Original Publication

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There are no restrictions on access to this document. An internet release form signed by the author to display this document online is on file with Towson University Special Collections and Archives.

Subjects

Abstract

In this study we examine the optical properties of a cobalt based ferrofluid when a magnetic field is applied. By performing optical transmission measurements we show that when a strong enough magnetic field is applied the ferrofluid behaves as a hyperbolic metamaterial. A hyperbolic metamaterial is a material that has unique optical properties which cause it to behave as a metal for one polarization direction of light and as a dielectric for the orthogonal polarization direction. By performing Fourier Transform Infrared (FTIR) spectroscopy we further demonstrate the unique properties of ferrofluid as hyperbolic metamaterial such as extreme sensitivity of the material to monolayer coatings of cobalt nanoparticles, which is relevant to applications in biological and chemical sensing. We also show that the ferrofluid can be used as a Minkowski spacetime analogue, where thermal fluctuations in our ferrofluid look similar to the creation and disappearance of individual Minkowski spacetimes.