Broadband graphene-on-silicon modulator with orthogonal hybrid plasmonic waveguides

Abstract

Graphene, a two-dimensional nanomaterial, possess unique photoelectric properties that have potential application in designing optoelectronic devices. The tunable optical absorption is one of the most exciting properties that can be used to improve the performance of silicon modulators. However, the weak light–matter interaction caused by the size mismatch between the optical mode fields and graphene makes the graphene-on-silicon modulator (GOSM) has large footprint and high energy consumption, limiting the enhancement of modulation efficiency. Here, we propose a broadband GOSM with orthogonal hybrid plasmonic waveguides (HPWs) at near-infrared wavelengths. The orthogonal HPWs are designed to compress the interaction region of optical fields and enhance the light-graphene interaction. The results show that the GOSM has a modulation depth of 26.20 dB/μm, a footprint of 0.33 μm2, a 3 dB modulation bandwidth of 462.77 GHz, and energy consumption of 2.82 fJ/bit at 1.55 μm. Even working at a broad wavelength band ranging from 1.3 to 2 μm, the GOSM also has a modulation depth of over 8.58 dB/μm and energy consumption of below 4.97 fJ/bit. It is anticipated that with the excellent modulation performance, this GOSM may have great potential in broadband integrated modulators, on-chip optical communications and interconnects, etc.

Optical Harmonic Generation in 2D Materials

“…OHG processes can be tuned through various techniques such as, exciton resonances, [ 112 ] gating, [ 59 ] stacking, [ 112 ] mechanical strain and pressure, [ 112 ] cavity generation, [ 303 ] and nanostructure engineering, [ 366 ] to optimize the performance of nonlinear devices. 2D material based nonlinear optics have been tested for applications involving lasers, [ 327 ] frequency converters, [ 367 ] waveguides, [ 368 ] THz wave generation, [ 361 ] spin/valleytronics, [ 253 ] and in the biomedical field. [ 369 ] Apart from that, 2D material based nonlinear devices are found to provide a variety of functionalities, for example, frequency converters, short pulse lasers, photodetector multifunctional modulator, [ 370 ] waveguides, [ 305,367,368,371 ] etc., as “all‐in‐one” solutions because of their diverse characteristics.…”

“…2D material based nonlinear optics have been tested for applications involving lasers, [ 327 ] frequency converters, [ 367 ] waveguides, [ 368 ] THz wave generation, [ 361 ] spin/valleytronics, [ 253 ] and in the biomedical field. [ 369 ] Apart from that, 2D material based nonlinear devices are found to provide a variety of functionalities, for example, frequency converters, short pulse lasers, photodetector multifunctional modulator, [ 370 ] waveguides, [ 305,367,368,371 ] etc., as “all‐in‐one” solutions because of their diverse characteristics. Such multifunctional optical devices have already begun to emerge (e.g., multifunctional modulator and modulator, and plasmonic waveguide).…”

Compact Low-Loss Electroabsorption Modulator Using a Graphene-Inserted Metal-Slot-Added Waveguide

“…It would be valuable to compare our EAM with other theoretically investigated graphene-based EAMs. Many previous works focused on just graphene-based nanoplasmonic waveguides, not considering their integration into a Si photonics platform [15]- [17], [19]. Those waveguides have better EAM characteristics than the GIMSA waveguide.…”

Low-Loss Graphene Waveguide Modulator for Mid-Infrared Waves

“…Meanwhile, graphene's optical and electrical properties can be easily tuned by bias voltage. Therefore, people can manually control the status of modulator based on graphene switch between on and off [10][11][12][13][14].…”