Wafer-scale fabrication of magneto-photonic structures in Bismuth Iron Garnet thin film

In this paper we report on a reproducible technological process for wafer-scale fabrication of different photonic structures in Bismuth Iron Garnet (BIG: Bi3Fe5O12) thin films: two-dimensional magneto-photonic crystals (PhC), ring circulators, Bragg gratings or ridge waveguides. Different fabrication techniques such as Ion Beam Etching (IBE), Focused Ion Beam (FIB) etching, wet chemical etching and Reactive Ion etching are compared. The transfer of different geometries in BIG is obtained with good etching verticality and conservation of the dimensions using Inductively Coupled Plasma Reactive Ion Etching (ICP-RIE). This work demonstrates the possibility of wafer-scale high-quality nanostructuration of crystalline garnet thin films for magneto-photonic devices.