For exploring a strong electro-optic effect from a graphene/hexagonal boron nitride (hBN) structure, here a comprehensive study for investigating the integrated broadband graphene/hBN modulators has been presented. Two representative configurations with a ${{\rm Si}_3}{{\rm N}_4}$ waveguide were compared, focusing on optimizing the hBN thickness, waveguide width and height, and graphene size to balance their performances. It was found that 200 µm long devices with 65 nm hBN thickness allow for $\sim{80}\;{\rm GHz}$ modulation bandwidth, 35.4 dB extinction ratio, and over 700 nm operation spectral range. Compared to the ridge ${{\rm Si}_3}{{\rm N}_4}$ waveguide, the buried ${{\rm Si}_3}{{\rm N}_4}$ waveguide was more suitable as an optical waveguide for the graphene/hBN modulator to obtain a large modulation depth of $\sim 0.17\;{\rm dB}\,{\unicode{x00B5}{\rm m}}$ and a large operation spectral range from 750 to $\sim{1640}\;{\rm nm}$.

中文翻译：

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基于Si ₃ N ₄波导的宽带石墨烯/六方氮化硼调制器

为了从石墨烯/六方氮化硼（hBN）结构中探索出强大的电光效应，本文对集成宽带石墨烯/ hBN调制器进行了全面研究。比较了具有$ {{\ rm Si} _3} {{\ rm N} _4} $波导的两种代表性配置，重点在于优化hBN厚度，波导宽度和高度以及石墨烯尺寸以平衡其性能。结果发现，具有65 nm hBN厚度的200 µm长器件可提供$ \ sim {80} \; {\ rm GHz} $调制带宽，35.4 dB的消光比以及超过700 nm的工作光谱范围。与脊$ {{\ rm Si} _3} {{\ rm N} _4} $波导相比，埋入的$ {{\ rm Si} _3} {{\ rm N} _4} $波导是更适合作为石墨烯的光波导/六方氮化硼调制器获得的一个大的调制深度$ \ SIM 0.17 \ {\ RM分贝} \ {\的unicode {x00B5} {\ RM米}} $和一个大操作光谱范围从750到$ \ sim {1640} \; {\ rm nm} $。