Comprehensive Modelling for Time-Dependent Magneto-Optical Transmission Spectrum of Hematite Ferrofluid

Abstract

Optical field enhancement maximization has been the ultimate objective of applications covering random lasers, spectroscopy, and -importantly- targeted drug delivery. Consequently, scientists resorted to plasmonic based approaches, which rendered the entire approach inapplicable due to biodegradability concerns. In another work, an experimental realization for a method of magneto-optical transmission maximization is reported. However, possible limitations on the higher excitation power needed for biomedical applications are still questionable. Furthermore, a comprehensive, quantitative understanding of all material and design related parameters influencing this enhancement is still needed for complete control over possible applications. Therefore, successfully derives a model for the magneto-optical transmission under a time-varying 0–4 kHz magnetic field, exhaustively accounting for material and design related phenomena; birefringence of hematite, dissipation, randomness, and anisotropy on the dielectric function, scattering cross-section, and polarizability, for the first time. The model achieves an accuracy of 99.99% over the band 300–1100 nm and exhausts the model limitations to the decay time constant of Cotton–Mouton co-effects. The dynamics of the problem are also derived, accounting for the influence of the magnetic field on the viscosity of the ferrofluid, which leads to an in-depth, required understanding of the magneto-optic interactions with ferrofluids for efficient applicability.