Gold Enhanced Graphene-Based Photodetector on Optical Fiber with Ultrasensitivity over Near-Infrared Bands

oleh: Wenguo Zhu, Songqing Yang, Huadan Zheng, Yuansong Zhan, Dongquan Li, Guobiao Cen, Jieyuan Tang, Huihui Lu, Jun Zhang, Zhijuan Zhao, Wenjie Mai, Weiguang Xie, Wenxiao Fang, Guoguang Lu, Jianhui Yu, Zhe Chen

Format: Article
Diterbitkan: MDPI AG 2021-12-01

Deskripsi

Graphene has been widely used in photodetectors; however its photoresponsivity is limited due to the intrinsic low absorption of graphene. To enhance the graphene absorption, a waveguide structure with an extended interaction length and plasmonic resonance with light field enhancement are often employed. However, the operation bandwidth is narrowed when this happens. Here, a novel graphene-based all-fiber photodetector (AFPD) was demonstrated with ultrahigh responsivity over a full near-infrared band. The AFPD benefits from the gold-enhanced absorption when an interdigitated Au electrode is fabricated onto a Graphene-PMMA film covered over a side-polished fiber (SFP). Interestingly, the AFPD shows a photoresponsivity of >1 × 10<sup>4</sup> A/W and an external quantum efficiency of >4.6 × 10<sup>6</sup>% over a broadband region of 980–1620 nm. The proposed device provides a simple, low-cost, efficient, and robust way to detect optical fiber signals with intriguing capabilities in terms of distributed photodetection and on-line power monitoring, which is highly desirable for a fiber-optic communication system.