Tunable dual plasmon-induced transparency and slow-light analysis based on monolayer patterned graphene metamaterial

We propose a novel terahertz metamaterial structure based on patterned monolayer graphene. This structure produces an evident dual plasmon-induced transparency (PIT) phenomenon due to destructive interference between bright and dark modes. Since the Fermi level of graphene can be adjusted by an external bias voltage, the PIT phenomenon can be tuned by adjusting the voltage. Then the coupled-mode theory (CMT) is introduced to explore the internal mechanism of the PIT. After that, we investigate the variation of absorption rate at different graphene carrier mobilities, and it shows that the absorption rate of this structure can reach 50%, which is a guideline for the realization of graphene terahertz absorption devices. In addition, through the study of the slow-light performance for this structure, it is found that its group index is as high as 928, which provides a specific theoretical basis for the study of graphene slow-light devices.

Understanding Disorder in Rectangular Dielectric Microcavity CROWs (Project Report 0642603-Y2)

This NSF-funded project [0642603] is a five-year (60 months) CAREER (Faculty Early Career Development Program) unified research and education development program, which focused on the physics and applications of optical waveguiding in the CROW (Coupled Resonator Optical Waveguide) structure. The CROW structure is suitable as the foundation of this project because it offers a very high four-wave mixing (FWM) nonlinearity based on the slow-light effects on each of the pump, signal and idler modes. The triple resonance effects can result in a large improvement of the nonlinear coefficient even with a modest improvement of the slowing factor. However, understanding the effects of disorder in CROWs is important, since it can limit the amount of slowing that can be achieved, and hence, the enhancement of slow-light enhanced nonlinearity.

Design and Fabrication of Long Silicon Microring CROWs (Project Report 0642603-Y3)

This NSF-funded project [0642603] is a five-year (60 months) CAREER (Faculty Early Career Development Program) unified research and education development program, with a focus on the physics and applications of optical waveguiding in the CROW (Coupled Resonator Optical Waveguide) device structure. The CROW structure is suitable as the foundation of this project because it offers a very high four-wave mixing nonlinearity based on the slow-light effects on each of the pump, signal and idler modes. Since the output depends quadratically on the propagation length (in the low power regime), it is important to realize long CROWs.