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

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

doi:10.3390/nano12010124

Abstract

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 × 104 A/W and an external quantum efficiency of >4.6 × 106% 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.

Highlights

IntroductionAs an optical to electrical signal converter, the photodetector is an indispensable element in every fiber-optic communication system [1,2,3,4]
In order to transfer the graphene onto the side-polished fiber (SPF), the poly (PMMA) was spin-coated onto the graphene film with a thickness of ~448 nm as a supporting layer
The graphene/PMMA film was transferred over the SPF

Summary

Introduction

As an optical to electrical signal converter, the photodetector is an indispensable element in every fiber-optic communication system [1,2,3,4]. Integrating photodetectors into optical fibers to achieve all-fiber photodetection is highly desirable, owing to the intriguing capabilities of distributed photodetection and on-line power monitoring, as well as their structural compactness [3,4]. Conventional photodetectors are based on Si, Ge; semiconductors cannot be perfectly integrated with optical fiber platforms, because of their different geometries and structures. The recently developed two-dimensional (2D) materials provide an opportunity for the all-fiber photodetector (AFPD) [3,4,5,6,7]. Several AFPDs are Nanomaterials 2022, 12, 124.

Methods

Results

Conclusion