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

Abstract

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.