Magneto-opotic crystal/magneto-optic film composite type structure Faraday rotator

Abstract

The invention discloses a magneto-optic crystal / magneto-optic film composite Faraday rotator, provided with a rare-earth iron garnet magneto-optic crystal and arranging a liquid-phase epitaxial iron garnet magneto-optic film layer on the rare-earth iron garnet magneto-optic crystal. The rare-earth iron garnet magneto-optic crystal has a composition: Re1xRe2yBi3-x-yFe5O12, where 1.5<x<2.8, 0.2<y<1.0, and Re1 stands for Yb, and Re2 stands for Tb, Ho and Y and they has positive and negative response to the wavelength coefficient of Faraday rotator, respectively. The composition of the said film layer is TbxBi3-xGaFe5-yO12, where 1.5<x<2.5, and 0<y<1.0. The invention has wide operating range and operating temperature internal and can make it possible for an wide-range (>50nm), wide-temperature range (-30 deg.C to +80 deg.C) optical isolator, which has an extremely great application value in the development of optical communication system, optical integration system, optical measurement system, and other systems.

Description

technical field [0001] The invention relates to optical communication and optical integration, in particular to a Faraday rotator with magneto-optic crystal / magneto-optic thin film composite structure. Background technique [0002] In recent years, with the development of optical communication, optical cable TV, and optical integration systems, an intelligent broadband optical fiber network has gradually formed, and the performance indicators such as bandwidth operating characteristics and temperature characteristics of optical isolators are more stringent. Taking polarization-sensitive optical isolators as an example, based on the conventional level of various companies at home and abroad, the current optical isolator products work at a center wavelength of 1550nm, with insertion loss < 0.5dB, and a working bandwidth of only about 20nm under the condition of reverse isolation > 40dB. , the working temperature range under the specified bandwidth index is 0℃~50℃. Howev...

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Problems solved by technology

Therefore, when λ=1550nm, the thickness of the 45° Faraday rotator is only 0.3mm, and the saturation magnetization of the crystal is low (about tens of thousands of A / m), but its Faraday rotation angle (θ f ) has large temperature coefficient FTC (-0.08deg / K) and wavelength coefficient FWC (0.14% / nm), so that the 45° Faraday rotator can work in the temperature range from -30°C to +80°C and the bandwidth requirement is 100nm Among them, the maximum deviation angles generated when the rotation angle is 45° are about 4.8° and 6.3° respectively, which will reduce the reverse isolation of the optical isolator to below 15dB and cannot work normally

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