摘要
基于表面等离子体的硅基集成光电探测器因具有THz带宽潜力而受到广泛关注.本文基于简化的两步光刻工艺实现表面等离子体狭缝波导与石墨烯相结合的光电导探测器,直接采用对称的狭缝波导金属作为微波电极,理论计算3-dB带宽大于120 GHz,受限于测试设备,实际测试的带宽大于70 GHz,实验上实现了72 Gbit/s NRZ和64 Gbit/s PAM-4等高速信号的接收,误码率均低于15%的软判决前向纠错码门限.由于表面等离子体增强了光和石墨烯的相互作用,在吸收区长度不大于7μm和偏置电压0.4 V的条件下,探测器的响应度大于0.13 A/W.该探测器解决了目前表面等离子体探测器普遍存在工艺复杂、高速性能受限于吸收材料载流子动态特性的问题,具备超小尺寸、高速大带宽、工艺简单和与CMOS工艺兼容的特点,有望在高速光互连、太赫兹发射以及太赫兹通信中得到应用.
Integrated silicon-based plasmonic photodetectors have attracted more and more attention recently,due to their potential applications in THz bandwidth.In this paper,by utilizing a simplified two-step lithography process,the photoconductive detector is fabricated with the core structure of plasmonic slot waveguide in two symmetric metallic slabs as microwave electrodes to integrate with mechanically exfoliated graphene.The 3-d B bandwidth of the graphene-on-plasmonic slot waveguide photodetector is exceeded 120 GHz under the theoretical calculation,and the measured bandwidth is still beyond 70 GHz due to the lack of larger-bandwidth equipment.High-speed data reception is demonstrated for 72 Gbit/s NRZ and 64 Gbit/s PAM-4 signals with a BER below 15%soft-decision FEC threshold.Based on the enhanced interactions of light and graphene induced by the subwavelength confinement from the plasmonic structure,the responsivity of 0.13 A/W is achieved under the condition of the 7-μm long detection zone and the 0.4-V bias voltage.With the advantages of ultra-compact,high-speed,large-bandwidth and compatible with the CMOS process,our photodetector has the potential to be used in high-speed optical interconnection,terahertz transmission and terahertz communication.
作者
王逸伦
黄鑫宇
周德
严其志
姜志滨
陈燎
李响
叶镭
张新亮
WANG YiLun;HUANG XinYu;ZHOU De;YAN QiZhi;JIANG ZhiBin;CHEN Liao;LI Xiang;YE Lei;ZHANG XinLiang(Wuhan National Laboratory for Optoelectronics,Huazhong University of Science and Technology,Wuhan 430074,China;School of Optical and Electronic Information,Huazhong University of Science and Technology,Wuhan 430074,China;Electrical Engineering Division,School of Engineering,University of Cambridge,Cambridgeshire CB31SE,UK)
出处
《中国科学：物理学、力学、天文学》
CSCD
北大核心
2021年第5期37-48,共12页
Scientia Sinica Physica,Mechanica & Astronomica
基金
国家自然科学基金(编号:61927817,61735006)
国家重点研发计划(编号:2019YFB2203100)资助项目。
