Faraday Rotation of Dy2O3, CeF3 and Y3Fe5O12 at the Mid-Infrared Wavelengths

David Vojna,Ryo Yasuhara,Hiroaki Furuse,Ondřej Slezák,Tomáš Mocek,Antonio Lucianetti

doi:10.3390/ma13235324

Abstract

The relatively narrow choice of magneto-active materials that could be used to construct Faraday devices (such as rotators or isolators) for the mid-infrared wavelengths arguably represents a pressing issue that is currently limiting the development of the mid-infrared lasers. Furthermore, the knowledge of the magneto-optical properties of the yet-reported mid-infrared magneto-active materials is usually restricted to a single wavelength only. To address this issue, we have dedicated this work to a comprehensive investigation of the magneto-optical properties of both the emerging (DyO ceramics and CeF crystal) and established (YFeO crystal) mid-infrared magneto-active materials. A broadband radiation source was used in a combination with an advanced polarization-stepping method, enabling an in-depth analysis of the wavelength dependence of the investigated materials’ Faraday rotation. We were able to derive approximate models for the examined dependence, which, as we believe, may be conveniently used for designing the needed mid-infrared Faraday devices for lasers with the emission wavelengths in the 2- spectral region. In the case of YFeO crystal, the derived model may be used as a rough approximation of the material’s saturated Faraday rotation even beyond the 2- wavelengths.

Highlights

A considerable amount of attention from the scientific community is currently directed towards the development of the mid-infrared lasers
We have investigated the CeF3 and Dy2 O3 material samples in the linear regime as such an arrangement corresponds to the usual, expected regime of operation of the paramagnetic materials in Unlike to the Dy2 O3 and CeF3, the YIG crystal sample was characterized in the saturated regime of the Faraday effect, in which the polarization rotation angle induced by the material does not grow further with an increasing strength of the applied magnetic field
We are going to present the results obtained by the Faraday rotation dispersion measurements along with the errors of the measurement and the fitting parameters of the models discussed in the previous section

Summary

Introduction

A considerable amount of attention from the scientific community is currently directed towards the development of the mid-infrared (mid-IR) lasers. The huge demand for the mid-IR lasers has inevitably led to an intensified development of the corresponding laser sources and optical components [1,7,8,9,10,11,12]. One of the most commonly used components in laser systems are those based on the Faraday effect, incorporating, for instance, magneto-optical modulators, polarization switches, rotators, deflectors, or isolators. All of these are frequently used for the polarization-based signal processing. The fundamental part of these devices is a piece of magneto-active material in which the plane of the polarized radiation is rotated by a certain angle as a result of applying the magnetic field

Methods

Results

Discussion

Conclusion