Publications by authors named "Yaw-Dong Wu"

In this paper, a general method for analyzing arbitrary planar negative-refractive-index (NRI) multilayer slab optical waveguide structures was proposed. Some degenerated examples were introduced to prove the accuracy of the proposed method. The analytical and numerical results show excellent agreement.

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We investigate the properties of ring resonators that are supported by a two-dimensional photonic crystal waveguide. The proposed structure composed of a photonic crystal ring resonator (PCRR) with four scatters can really function as a wavelength division multiplexer. The significance of the design is that the output waveguide is perpendicular to the ring resonator.

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We propose new all-optical logic gates containing a local nonlinear Mach-Zehnder interferometer waveguide structure. The light-induced index changes in the Mach-Zehnder waveguide structure make the output signal beam propagate through different nonlinear output waveguides. Based on the output signal beam propagating property, various all-optical logic gates by using the local nonlinear Mach-Zehnder waveguide interferometer structure with two straight control waveguides have been proposed to perform XOR/NXOR, AND/NAND, and OR/NOR logic functions.

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An ultrasmall device size optical interleaver based on directional coupler waveguides in two-dimensional photonic crystals (PCs) is proposed. The numerical results show that the proposed PCs waveguide structure could really function as an interleaver with the central wavelength 1550 nm and the channel spacing 0.8 nm (frequency spacing of 100 GHz) of the dense wavelength division multiplexing (DWDM) specification.

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We proposed a new all-optical switch by using the phase modulation of spatial solitons. The proposed structure is composed of the nonlinear Mach-Zehnder interferometer (MZI) with the straight control waveguide, the uniform nonlinear medium and the nonlinear output waveguides. The local nonlinear MZI functions like a phase shifter.

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We propose a general method for analyzing a multilayer optical waveguide with all nonlinear layers. This general method can be degenerated into some special cases, such as symmetric or asymmetric nonlinear optical waveguide structures, the intensity-dependent refractive index with self-focusing nonlinear medium, hollow waveguides, and multilayer systems. Based on this general method, the analysis and calculation of complicated multilayer optical planar waveguides can be achieved easily.

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This work demonstrated a new approach of planar multi-channel wavelength division multiplexing (WDM) system using photonic crystal structures. The system consists of a waveguide that is realized by a defect row of photonic crystal and high Q-value micro-cavities with asymmetric super-cell design. Two-Dimension (2-D) Finite-Difference-Time-Domain (FDTD) method is performed for simulation in this paper.

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We propose an all-optical switching device based on the interaction property between optical spatial solitons. By launching the nonlinear symmetric modes for the relative phase relation pi into the uniform nonlinear medium, the repulsive property between spatial solitons will be observed. Based on the repulsive property, a new all-optical switching device will be proposed.

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We propose a novel method for analyzing a multilayer optical waveguide structure with all nonlinear guiding films. This method can also be used to analyze a multibranch optical waveguide structure with all nonlinear guiding branches. The results show that agreement between theory and numerics is excellent.

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We proposed a new all-optical switching device by using the phase modulation of spatial solitons. The proposed structure is composed of an asymmetric nonlinear Mach-Zehnder interferometer (NMZI) with different lengths for the two arms, the uniform nonlinear medium, and the nonlinear output waveguides. The asymmetric NMZI functions like a phase shifter.

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We propose a novel all-optical wavelength auto-router based on spatial solitons. By using the swing effect of spatial solitons in a Kerr-type nonlinear medium, the proposed nonlinear waveguide structure could function as a self-routing wavelength division multiplexer (WDM). It could be a potential key component in the applications of ultra-high-speed and ultra-high-capacity optical communications and optical data processing systems.

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