Cao Yue, Lin Baizhu, Sun Yue, Che Xinchi, Yi Yunji, Wang Fei, Zhang Daming
State Key Laboratory of Integrated Optoelectronics, College of Electronic Science & Engineering, Jilin University Changchun 130012 P. R. China
RSC Adv. 2018 Aug 31;8(54):30755-30760. doi: 10.1039/c8ra06038j. eCollection 2018 Aug 30.
Graphene-embedded waveguide filters have been widely used in the areas of polarization and mode filtering because of their characteristics of easy fabrication, high integration, and high extinction ratio. In this article, we propose thermal tuning filters based on a graphene-embedded polymer-silica hybrid waveguide. Compared to previously reported filters, this device can realize the efficient adjustment of the relative position between the optical field and graphene layer by thermal tuning. Consequently, the polarization and mode filtering properties of the filter can be adjusted by thermal tuning. This high-efficiency tuning characteristic is due to the opposite thermo-optic coefficient of the polymer and silica material. Furthermore, a layer with a low refractive index is embedded in the polymer-silica hybrid core to increase the tuning efficiency. The optical absorption, mode properties, and thermal field distributions were simulated. It was found that such single-mode filters could realize E -pass or E -stop selection, and the attenuation variation (Δ) was optimized to 32.20 dB cm (E mode) using the top electrode and air trench structure with Δ = 10 K and = 48.39 mW in the single-mode waveguide. For the multimode waveguide filters, the attenuation variation (Δ) of the E modes (E , E , and E ) was also calculated. Such thermal tuning filters were found to be compatible with chemical potential regulation graphene modulators and filters, and they can be applied to broadband photonic integrated circuits and mode division multiplexing systems.
石墨烯嵌入式波导滤波器因其易于制造、高集成度和高消光比等特性，已在偏振和模式滤波领域得到广泛应用。在本文中，我们提出了基于石墨烯嵌入式聚合物 - 二氧化硅混合波导的热调谐滤波器。与先前报道的滤波器相比，该器件可通过热调谐实现光场与石墨烯层之间相对位置的有效调节。因此，滤波器的偏振和模式滤波特性可通过热调谐进行调整。这种高效调谐特性归因于聚合物和二氧化硅材料相反的热光系数。此外，在聚合物 - 二氧化硅混合纤芯中嵌入一层低折射率材料以提高调谐效率。对光吸收、模式特性和热场分布进行了模拟。结果发现，此类单模滤波器可实现E模通过或E模截止选择，在单模波导中，利用顶电极和空气槽结构，当Δ = 10 K且 = 48.39 mW时，衰减变化（Δ）优化至32.20 dB/cm（E模）。对于多模波导滤波器，还计算了E模（E 、E 和E ）的衰减变化（Δ）。发现此类热调谐滤波器与化学势调控石墨烯调制器和滤波器兼容，可应用于宽带光子集成电路和模式分复用系统。
