TBOR-shaped electro-optic modulator with dual output based on double-layer graphene

• Published in: Physics letters. A 2019-01, Vol.383 (6), p.578-584
• Main Authors: Li, Zhiquan, Bai, Landi, Gu, Erdan, Xie, Ruijie, Li, Xin, Li, Wenchao
• Format: Article
• Language: English
• Subjects: Coupled-mode theory; Graphene; Optical modulation
• ISSN: 0375-9601; 1873-2429
• DOI: 10.1016/j.physleta.2018.11.030

We proposed an electro-optic modulator with two-bus one-ring (TBOR) structure to improve the extinction ratio and reduce insert loss. It has a dual output compared with one-bus one-ring structure. In addition, double-layer graphene makes it possible for the modulation in the visible to mid-infrared wavelength range. It shows that this new electro-optic modulator can present two switching states well with low insertion loss, high absorption and high extinction ratio. At λ=1550 nm, when the switching states are based on the chemical potential, μc=0.38 eV and μc=0.4 eV, the insertion losses of both output ports are less than 2 dB, the absorption of the output port coupled via a micro-ring reaches 45 dB and the extinction ratio reaches 14 dB. When the refractive index of the dielectric material is 4.2, the applied voltage will be less than 1.2 V, thus can be used in low-voltage CMOS technology. •The design can achieve a single input and dual output function well.•Double-layer graphene is used as the tunable material.•TBOR-shaped structure is used having highly improved its modulation.•Both outputs achieve a low insertion loss and high absorption near λ=1550 nm.•The applied voltage can reduce to 1.2 V matching the low-voltage CMOS technology.