In this Letter, we theoretically study the topological plasmons in Su-Schrieffer-Heeger (SSH) model-based graphene nanoribbon (GNR) layers. We find that for the one-dimensional (1D) stacked case, only two topological modes with the field localized in the top or bottom layer are predicted to exist by the Zak phase. When we further expand the stacked 1D GNR layers to two-dimensional (2D) arrays in the in-plane direction, the topology is then characterized by the 2D Zak phase, which predicts the emergence of three kinds of topological modes: topological edge, surface, and corner modes.
View Article and Find Full Text PDFWe propose to achieve multi-band perfect plasmonic absorptions with peak absorptivity >99% via the excitation of standing-wave graphene surface plasmon polaritons using single-layer graphene-based rectangular gratings. For the case with continuous gratings, perfect absorptions are only allowed for even-order modes, while the absorptions are quite low for odd-order modes because the fields are out-of-phase. However, for gratings with bottom-open configuration, four-band perfect absorptions containing both the even- and odd-order modes can be realized, which are found to be highly sensitive to the incident angle.
View Article and Find Full Text PDFGraphene nanoribbon (GNR), as a fundamental component to support the surface plasmon waves, are envisioned to play an important role in graphene plasmonics. However, to achieve extremely confinement of the graphene surface plasmons (GSPs) is still a challenging. Here, we propose a scheme to realize the excitation of localized surface plasmons with very strong field enhancement at the resonant frequency.
View Article and Find Full Text PDFAn erratum is presented to correct the typing mistake in a equation in Sect. 3.1 of [Opt.
View Article and Find Full Text PDFTo achieve efficiently coupling to external light is still remaining an insurmountable challenge that graphene faces before it can play an irreplaceable role in the plasmonic field. Here, this difficulty is overcome by a scheme capable of exciting graphene surface plasmons (GSPs) in in-plane bended gratings that are formed by elastic vibrations of graphene nanoribbons (GNRs). The gratings enable the light polarized perpendicularly to the GNRs to two kinds of GSP modes, of which the field concentrations are within the grating crest (crest mode, C-M) and trough (trough mode, T-M), respectively.
View Article and Find Full Text PDFWe reported on the generation of femtosecond pulse in a fiber ring laser by using a polyvinyl alcohol (PVA)-based topological insulator (TI), Bi2Se3 saturable absorber (SA). The PVA-TI composite has a low saturable optical intensity of 12 MW/cm2 and a modulation depth of ~3.9%.
View Article and Find Full Text PDFWe report on the generation of passive harmonic mode locking of a fiber laser using a microfiber-based topological insulator (TI) Bi(2)Te(3) saturable absorber (SA). The optical deposition method was employed to fabricate the microfiber-based TISA. By virtue of the excellent nonlinear optical property of the proposed TISA, the fiber laser could operate at the pulse repetition rate of 2.
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