• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.11
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• pp.43-48
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• 2010

The main features of a dielectric-loaded surface plasmon polariton waveguide are analyzed such as mode effective index and propagation length. These parameters are calculated using the finite element method for different metal-polymer pairs while varying the ridge width and thickness. As a performance metric, we employ the 2D figure of merit including two conflicting parameters i.e. mode effective index and propagation length. The results obtained here allow one to identify the parameter range for realizing the dielectric-loaded surface plasmon polariton waveguide and to choose dimension and material of the ridge for subwavelength confinement and moderate propagation loss at telecom wavelengths.

• Journal of the Optical Society of Korea
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• v.14 no.3
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• pp.277-281
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• 2010

We propose a design and optimization method for a dielectric-loaded surface plasmon polariton waveguide using a genetic algorithm. This structure consists of a polymer ridge on top of two layers of substrate and gold film. The thickness, width and refractive index of the ridge are designed to optimize the figures of merit including mode confinement and propagation length. The modal analysis combined with the effective index method shows that the designed waveguide exhibits a fundamental propagation mode with high mode confinement while ensuring that the propagation loss remains relatively low.

• Carbon letters
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• v.25
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• pp.84-88
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• 2018

At present, an important research area is the search for materials that are compatible with CMOS technology and achieve a satisfactory response rate and modulation efficiency. A strong local field of graphene surface plasmon polariton (SPP) can increase the interaction between light and graphene, reduce device size, and facilitate the integration of materials with CMOS. In this study, we design a new modulator of SPP-based cycle branch graphene waveguide. The structure comprises a primary waveguide of graphene-$LiNbO_3$-graphene, and a secondary cycle branch waveguide is etched on the surface of $LiNbO_3$. Part of the incident light in the primary waveguide enters the secondary waveguide, thus leading to a phase difference with the primary waveguide as reflected at the end of the branch and interaction coupling to enhance output light intensity. Through feature analysis, we discover that the area of the secondary waveguide shows significant localized fields and SPPs. Moreover, the cycle branch graphene waveguide can realize gain compensation, reduce transmission loss, and increase transmission distance. Numerical simulations show that the minimum effective mode field area is about $0.0130{\lambda}^2$, the gain coefficient is about $700cm^{-1}$, and the quality factor can reach 150. The structure can realize the mode field limits of deep subwavelength and achieve a good comprehensive performance.

• ETRI Journal
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• v.29 no.6
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• pp.808-810
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• 2007

We demonstrate 10 Gbps optical signal transmission via long-range surface plasmon polaritons (LR-SPPs) in a very thin metal strip-guided geometry. The LR-SPP waveguide was fabricated as a 14 nm thick, 2.5 ${\mu}m$ wide, and 4 cm long gold strip embedded in a polymer and pigtailed with single-mode fibers. The total insertion loss of 16 dB was achieved at a wavelength of 1.55 ${\mu}m$ as a carrier wave. In a 10 Gbps optical signal transmission experiment, the LR-SPP waveguide exhibits an excellent eye opening and a 2.2 dB power penalty at $10^{-12}$ bit error rate. We confirm, for the first time, that LR-SPPs can efficiently transfer data signals as well as the carrier light.

• Journal of the Semiconductor & Display Technology
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• v.8 no.3
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• pp.7-11
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• 2009

In this paper, we developed and presented a design result for optimizing the geometry of Ag circular SPP waveguide for subwavelength waveguide applications. We investigated the effect of the design parameters on the light propagation and find the optimum design for small modal size, high coupling coefficient, and low sensitivity. The results show that the globally optimal design locates optimal waveguide geometries more efficiently than individual optimal points for multivalued objective function.

• Journal of the Semiconductor & Display Technology
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• v.9 no.2
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• pp.97-102
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• 2010

Propagation modes of symmetric metal-insulator-metal SPP waveguides are analyzed. Main characteristics of these waveguides such as mode effective index, propagation length, and penetration depths are calculated at the telecom wavelength for different layer thickness. We adopt Au, Al as a metal material and air, glass as a dielectric material and obtain different optical characteristics. The surface plasmon characteristics in this paper provide a numerical insight for designing nanostructure metal plasmon waveguide.

• Journal of the Optical Society of Korea
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• v.16 no.1
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• pp.70-75
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• 2012

An optimization methodology for designing a dielectric-filled plasmonic slot waveguide is presented. The genetic algorithm combined with a rigorous analysis based on the finite element method is used to optimize a nano-scaled plasmonic slot waveguide to have high mode confinement and a long propagation length, for which the objective function is defined as a figure of merit combining both propagation parameters.

• Journal of the Optical Society of Korea
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• v.15 no.3
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• pp.305-309
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• 2011

We present an efficient design approach for a plasmonic slot waveguide using a genetic algorithm. The analyzed structure consists of a nanometric slot in a thin metallic film embedded within a dielectric. To achieve high confinement without long propagation length, the thickness and width of the slot are optimally designed in order to optimize the figures of merit including mode confinement and propagation length. The optimized design is based on the finite element method and enhances the guiding and focusing of light power propagation.

• Korean Journal of Optics and Photonics
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• v.19 no.6
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• pp.429-434
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• 2008

We propose a wavelength filter based on long-range surface plasmon-polaritons (LR-SPP) supported by a asymmetric doubleelectrode LR-SPP structure. For the case of the asymmetric double-layered LR-SPP waveguide, LR-SPPs exist with a much broader range of index mismatches between core and clad materials. Thus, the asymmetric double-electrode LR-SPP waveguide is adequate to form a plasmonic band-gap device as we report in this paper by studying Bragg-reflection wavelength filter based on it. The structure for wavelength filter operating telecommunications wavelength is designed by using the method of line (MoL) and the transfer matrix method. The fabricated device shows a relatively high extinction ratio of 50 dB with a bandwidth of 2 nm, and the performance is very consistent with numerical simulations.

• Korean Journal of Optics and Photonics
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• v.17 no.4
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• pp.371-380
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• 2006

We design and fabricate a novel tunable wavelength filter, which utilizes long-range surface plasmon-polaritons excited along nm-thick-metal strips. A gold metal strip, with $\sim$ cm length, 20 nm thickness, and $\sim$ 5$\mu$m width, is embedded in thick thermo-optic Polymer films supported by a silicon wafer. A dielectric Bragg grating structure is Placed on the metal strip, so that transmission signals at telecom wavelength are selected by thermal effect of the thermo-optic polymer. High extinction ratio of 25 dB and total insertion loss of $\sim$25 dB/cm can be measured by single-mode coupling of optical fibers. We also verify that wavelength tuning of the long-range surface plasmon-polariton filters can be achieved by electric current directly applied to the metal-strip waveguides.