We propose an ultra-compact graphene-based plasmonic modulation that is compatible with complementary metaloxide- semiconductor processing. The proposed structure uses a monolayer graphene as a mid-infrared surface waveguide, whose optical response is spatially modulated using electric fields to form a Fabry-Perot cavity. By varying the voltage acting on the cavity, the transmitted wavelength of the device could be controled at room temperature. The finite element method (FEM) has been employed to verify our designs. This design has potential applications in the graphene-based silicon optoelectronic devices as it offers new possibilities for developing new ultra-compact spectrometers and low-cost hyperspectral imaging sensors in mid-infrared region.
A novel hybrid plasmonic waveguide of the graphene-coated V-groove and waveguide structure is proposed. The
subwavelength confinements and the propagation of the graphene surface plasmon polaritons modes of the hybrid
graphene-coated waveguide are reached. The mode field energies can be well confined in the V-groove or the waveguide
and be adjusted by varying the chemical potential of graphene. The mode confinement becomes weaker and the
propagation length gets longer as the chemical potential of grapheme increasing. In addition, adjusting the radius of the
waveguide and the frequencies could change the mode propagation and the higher mode is achieved. The finite element
method (FEM) has been employed to study the mode distributions and electromagnetic responses of our designs at midinfrared
In this paper, we investigate a monolayer graphene placed on a doped-silicon grating numerically and studied the
dependence of its transmission spectra on the geometrical parameters of the grating. A stop-band with great tunability in
the mid-infrared region of the transmission spectra are obtained in a much more compact structure size compared to a
traditional fiber Bragg grating (FBG). In addition, by inserting a defect into the center of the structure, we introduce a
phase shift of π phase shift into the field, leading to an open window in the stop-band transmission spectra. With the
good tunability and compact size, our proposed structure can be utilized as graphene-based ultra-compact and highly
sensitive plasmonic senors for potential applications.
Electromagnetically induced transparency (EIT) has been proposed numerically in the plasmonic waveguides composed of unsymmetrical slots shaped metal–insulator-metal (MIM) structures. By the transmission line theory and Fabry-Perot model, the formation and evolution mechanisms of Plasmon induced transparency are exactly analyzed. The analysis shows that the peak of EIT-like transmission can be changed easily according to certain rules by adjusting the geometrical parameters of the slot structures, including the coupling distances and slot depths. We can find a new method to design nanoscale optical switch, devices in optical storage and optical computing. It is found that the slow light effects are emerged in the unsymmetrical slot structures. A small group velocity(c/80) can be achieved.