Magneto-optical switching in microcavities based on a TGG defect sandwiched between periodic and disordered one-dimensional photonic structures

TL;DR

This paper demonstrates the simulation of magneto-optical microcavities using TGG defect layers, showing a 22 nm tuning of defect modes with magnetic fields and exploring tuning in disordered structures for contactless optical control.

Contribution

It introduces a simulation-based approach for magneto-optical tuning of microcavities with TGG defects and extends the concept to disordered photonic structures for broad resonance shifts.

Findings

22 nm defect mode tuning at 5 T magnetic field

Tuning demonstrated at low temperature (8 K)

Resonance shifts in disordered structures under magnetic field

Abstract

The employment of magneto-optical materials to fabricate photonic crystals gives the unique opportunity to achieve optical tuning by applying a magnetic field. In this study we have simulated the transmission spectrum of a microcavity in which the Bragg reflectors are made with silica (SiO2) and yttria (Y2O3) and the defect layer is made with TGG (Tb3Ga5O12). We show that the application of an external magnetic field results in a tuning of the defect mode of the microcavity. In the simulations we have considered the wavelength dependence of the refractive indexes and the Verdet constants of the materials. A tuning of the defect mode of about 22 nm with a magnetic field of 5 T, at low temperature (8 K), is demonstrated. Furthermore, we discuss the possibility to tune a microcavity with disordered photonic structures as reflectors. In the presence of the magnetic field such microcavity shows a shift of resonances in a broad range of wavelengths. This study presents a method of contactless optical tuning.