面向宽带光隔离器的一维磁光子晶体结构

One-dimensional magneto-photonic crystals with flat-top responses for Magneto-optical isolators

文章采用4×4传输矩阵法研究了两种一维磁光子晶体结构的宽带光隔离特性.结构一在外加磁场与光路光轴方向呈41.0°角时,用22.90μm的总厚度实现了3 nm的宽带光隔离,且在宽带范围内法拉第旋转角和透射率分别在45°~48.89°和99.86~99.95%之间波动,此结构在宽带范围内均可实现稳定的光隔离;结构二在外加磁场与光路光轴方向平行时,用18.61μm的总厚度实现了1 nm的宽带光隔离,且在宽带范围内法拉第旋转角和透射率分别在45.83°~45.89°和98.53~98.78%之间波动,此结构无需调节外加磁场角度即可实现光隔离.

The 4 × 4 transfer matrix method is used to investigate the broadband optical isolation property of two different one-dimensional magneto-photonic crystal structures. The results showthat the first structure makes broadband optical isolation come true. When the angle between the applied magnetic field and optical axis is set as 41. 0°,its bandwidth achieved 3 nm with a 22. 90 μm-thickness,the Faraday rotation angle fluctuated from 45° to 48. 89° and transmittance achieved 99. 86 ~ 99. 95%. The other structure with total thickness of 18. 61 μm achieves a 1 nm-bandwidth optical isolation with the Faraday rotation angle fluctuated from 45. 83° to 45. 89° and transmittance fluctuated from 98. 53% to98. 78%,when the applied magnetic field is nearly parallel to the optical axis. This structure ensures the achievement of optical isolation without adjusting the applied magnetic field.