Non-Linear Microwave and Magneto-Optical Properties of Ferrite Films

Abstract

Ferrite films of YIG have currently found various applications. These films grown usually by the liquid-phase epitaxy method possess a good quality suitable for both microwave and optic waves applications. These films with the thickness in few (or tens) of microns and lateral dimensions in one or even few centimeters possess properties of a ferromagnetic medium at the frequency range from 1 to 20 GHz. This frequency range is intensively studied due to the possibility to excite and investigate traveling magnetostatic spin waves (MSW). On the other hand, in the infrared frequency range between 1.1 and 6 µm YIG films find applications due to the strong efficiency of magneto-optic interactions. Light propagates in such films in the form of wave-guided modes and they become coupled and be converted due to strong Faraday and Cotton-Mouton magneto-optic effects. Usually YIG films are used for the purposes of strong optical mode conversion and this finds different applications. The most interesting applications can be, however, achieved when both microwave and light waves propagate simultaneously in such films. The possibility of such films to support these waves is used for effective magneto-optic Bragg interaction between waves [1,2]. Frequencies and wave-numbers of MSW are usually much smaller than the respective values for light. Thus under the special relation between the wave-numbers of the incident and diffracted light modes and the MSW wave-number, the anisotropic Bragg diffraction of light can be quite strong. This can find various interesting applications.