Magneto-optical nanoparticle-doped silica-titania planar waveguides

Abstract

This letter describes how composite material, made of maghemite (γ-Fe2O3) nanoparticles embedded in a silica∕titania matrix, can be used to develop new magneto-optical planar waveguides. Thin film samples are coated on Pyrex™ substrates from a magnetic particles doped sol-gel preparation. M-lines spectroscopy measurements performed on these samples show that an out of plane magnetic field applied during the gelation induces a decrease of the planar waveguide phase mismatch. Free space measurements evidence the Faraday rotation of the films up to 25°∕cm at 633 nm. Improvements and leads of further works are proposed in term of magneto-optical waveguide applications.

Low birefringent magneto-optical waveguides fabricated via organic-inorganic sol-gel process

“…Previous results have shown the potentiality of such a material [8]. However, the magneto-optical conversion of the components was limited by a too important value of the matrix birefringence and by a too low intrinsic Faraday rotation of the nanoparticles [8].…”

“…Comparison between hybrid and mineral sol-gel lm Table 3 presents a simple comparison of the intrinsic birefringence of waveguides elaborated via organic-inorganic hybrid sol-gel process and those made of mineral sol-gel process (studied by F. Royer et al [8]). It also gives a composition of the fundamental modal birefringence ∆N 0 in geometrical part ∆N geo and intrinsic part ∆n i , assuming a homogenous intrinsic anisotropy.…”

“…However, the magneto-optical conversion of the components was limited by a too important value of the matrix birefringence and by a too low intrinsic Faraday rotation of the nanoparticles [8]. In this article, we present the possibility to improve theses properties by using an organic-inorganic sol-gel matrix and cobalt ferrite (CoFe 2 O 4 ) nanoparticles.…”

“…It also gives a composition of the fundamental modal birefringence ∆N 0 in geometrical part ∆N geo and intrinsic part ∆n i , assuming a homogenous intrinsic anisotropy. The mineral thin lms were fabricated from a sol-gel preparation of non photopolymerisable methyltriethoxysilicate (MTEOS) and tetrabuthylorthotitanate (Ti(OBu) 4 ) with a mixed solution of C 2 H 5 OH and diluted HCl (see [8] for details). This table conrms that, in each case, the geometrical birefringence is relatively low compared to the intrinsic one and that the intrinsic birefringence is the source component of the modal birefringence (around ∆N 0 ).…”

Hybrid magneto-optical mode converter made with a magnetic nanoparticles-doped SiO2/ZrO2 layer coated on an ion-exchanged glass waveguide

“…Magneto-optical thin films are obtained by dipping a substrate in this solution and baking it at 90 C during 1 h. Using Pyrex TM substrate, promising magneto-optical characteristics illustrated by a specific Faraday rotation of 310 /cm and a refractive index of 1.51(@1550 nm) have been reported. 6,7 In this letter we report how such a magneto-optical layer can be used with glassy integrated circuits in order to realize hybrid mode converter.…”