Large Faraday Magneto-Optic Garnet Film Materials And Its Application Research In Magneto-Optic Switch

With the popular use of the Internet, the development of all-optical networkbecome faster serve the needs of our time. Optical switch is an important part of theall-optical network. Compared to other optical switch, magneto-optical switch has manyadvantages such as high speed, high stability, low driving voltage and low crosstalk.The materials with magneto-optic effect are the core component of the optical switch.Materials with a large Faraday magneto-optic effect are of great effect to improve theperformance of the switch. Due to the lagged development of magneto-optic thin film,the practical application of magneto-optic switch device for size, volume, weight,integration and stability are relatively poor, so the research of magneto-optic materialsbecomes more and more. This article is the study of the large Faraday magneto-opticalmaterials and its application in magneto-optical switch.Firstly, we use RF magnetron sputtering to prepare different doping concentrationof Bi:YIG and Ce:YIG polycrystalline thin films under different conditions. Afterannealing, we analyze the microscopic and macroscopic properties of these films andget the best condition to achieve big Faraday rotation angle. We prepare with largeFaraday magneto-optic effect of garnet film, which reaches to the requirement ofmagneto-optic switch. When the sputtering atmosphere is5sccmAr+4%O2, annealingtemperature is680℃, the Faraday rotation coefficient of the Bi1.5:YIG thin film is1.99°/μm. When the sputtering atmosphere is5sccmAr+10%O2, annealing temperatureis680℃and annealing atmosphere is hydrogen, the Faraday rotation coefficient of theCe1.2:YIG thin film is1.22°/μm. At the same time, lead-free BiLuIG single crystal thinfilm was prepared by liquid phase epitaxy. The film has less surface defects and highflatness. The Faraday rotation coefficient of this film is2.1°/μm. At last we prepare withlarge Faraday magneto-optic effect of garnet film successfully by both two methods.Finally, we design the light path, circuit and magnetic circuit of the magneto-opticswitch according to the principle of magneto-optic switch. We design a pulse currentgenerator to drive the coil. By controlling the current plus to drive the magnetic field tomagnetize thin film, then the linear polarized light will be rotated when it passed through the material. The switch can be on and off. We use GSF film as themagneto-optical material. We make a real one according the design and take it to simpletest.