An electrically tunable plasmonic optical modulator with high modulation depth based on graphene-wrapped silver nanowire. (15th November 2016)

• Record Type: Journal Article
• Authors: Zhang, C; Tu, L; Huang, Z; Liu, L; Zhan, P; Sun, C; Wang, Z
• Is Part Of: Journal of optics. Volume 18:Number 12(2016:Dec.)
• Publication Date: 2016-11-15
• Subjects: modulators -- waveguides -- plasmonics -- graphene; Optics -- Periodicals; 535.05
• DOI: 10.1088/2040-8978/18/12/125007
• Languages: English
• ISSNs: 2040-8978

Abstract

Abstract: We report a systematic study of a graphene-wrapped plasmonic optical modulator with a high modulation depth. The optical modulator consists of a silver (Ag) nanowire as a single mode plasmonic waveguide being wrapped with a graphene monolayer as an electrically controllable absorbing material. While a thin dielectric spacing layer is used to electrically isolate the Ag nanowire from the graphene monolayer, we find it further promotes higher optical absorption by manipulating a strong electric field at its outer surface, where the graphene layer is located. By optimizing the dielectric layer thickness as well as the Ag nanowire radius, a strong optical modulation of 0.46 dB μ m −1 with a high-speed characteristic at the operating wavelength of 785 nm is achieved. This design is further implemented at the telecommunication wavelength (1550 nm) with an optimized modulation depth of 1.07 dB μ m −1 .