| 61. |
- Wang, J., et al.
(författare)
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Sub-μm2 power splitters by using silicon hybrid plasmonic waveguides
- 2011
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Ingår i: Optics Express. - : Optical Society of America. - 1094-4087. ; 19:2, s. 838-847
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Tidskriftsartikel (refereegranskat)abstract
- Nano-scale power splitters based on Si hybrid plasmonic waveguides are designed by utilizing the multimode interference (MMI) effect as well as Y-branch structure. A three-dimensional finite-difference time-domain method is used for simulating the light propagation and optimizing the structural parameters. The designed 1×2 50:50 MMI power splitter has a nano-scale size of only 650 nm×530 nm. The designed Y-branch power splitter is also very small, i.e., about 900 nm×600 nm. The fabrication tolerance is also analyzed and it is shown that the tolerance of the waveguide width is much larger than±50 nm. The power splitter has a very broad band of over 500 nm. In order to achieve a variable power splitting ratio, a 2×2 two-mode interference coupler and an asymmetric Y-branch are used and the corresponding power splitting ratio can be tuned in the range of 97.1%:2.9%-1.7%:98.3% and 84%:16%-16%:84%, respectively. Finally a 1×4 power splitter with a device footprint of 1.9 μm×2.6 μm is also presented using cascaded Y-branches.
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| 62. |
- Wang, Zhechao, et al.
(författare)
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Experimental demonstration of an ultracompact polarization beam splitter based on a bidirectional grating coupler
- 2009
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Ingår i: 2009 Asia Communications and Photonics Conference and Exhibition, ACP 2009. - 9781557528773 ; , s. 5377257-
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Konferensbidrag (refereegranskat)abstract
- A bidirectional grating serving both as a polarization beam splitter and a vertical coupler for Silicon on Insulator nanophotonic circuits is fabricated and characterized. The measured coupling efficiency is as high as 43%. The demonstrated device has a large 3-dB bandwidth and a high extinction ratio between two orthogonal polarizations.
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| 63. |
- Wang, Zhechao, et al.
(författare)
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Polarization-insensitive ultrasmall microring resonator design based on optimized Si sandwich nanowires
- 2007
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Ingår i: IEEE Photonics Technology Letters. - 1041-1135 .- 1941-0174. ; 19:17-20, s. 1580-1582
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Tidskriftsartikel (refereegranskat)abstract
- Bent Si sandwich nanowires are used and optimized to obtain an ultrasmall polarization-insensitive microring resonator (MRR). The used Si sandwich nanowire has a low refractive index layer between two Si layers with high refractive indexes. By optimizing the refractive index and thickness of the sandwiched layer, the bent Si sandwich nanowire becomes nonbirefringent theoretically. The designed nonbirefringent nanowire has a relatively good fabrication tolerance. By using such a nonbirefringent bent Si sandwich nanowire, an ultrasmall polarization-insensitive MRR is designed.
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| 64. |
- Wang, Zhechao, et al.
(författare)
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Ultracompact low-loss coupler between strip and slot waveguides
- 2009
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Ingår i: Optics Letters. - 0146-9592 .- 1539-4794. ; 34:10, s. 1498-1500
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Tidskriftsartikel (refereegranskat)abstract
- We present both theoretical and experimental results of an ultracompact waveguide coupler that is capable of highly efficient coupling of light from strip waveguides to slot waveguides, and vice versa. By optimizing the geometrical parameters, it is possible to achieve extremely low-loss coupling. A coupling efficiency of 97% has been obtained experimentally while keeping the overall size down to the range below 10 mu m. Further analysis shows that the proposed coupler has relatively high tolerance to fabrication errors and is wavelength insensitive. (C) 2009 Optical Society of America
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| 65. |
- Wang, Zhechao, et al.
(författare)
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Ultrasmall Si-nanowire-based polarization rotator
- 2008
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Ingår i: Journal of the Optical Society of America. B, Optical physics. - 0740-3224 .- 1520-8540. ; 25:5, s. 747-753
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Tidskriftsartikel (refereegranskat)abstract
- A polarization rotator based on asymmetrical Si nanowires is presented and optimized for high polarization rotation efficiency (almost 100%). The present polarization rotator has a very small conversion length (similar to 10 mu m) and consequently becomes very compact. The analysis of the wavelength dependence shows the present polarization rotator has a broad bandwidth (similar to 120 nm) for high conversion efficiency (> 97%). The tolerance to various fabrication errors is also numerically studied. To compensate the fabrication error, a post-compensation method is introduced by modifying the refractive index of the up-cladding. (c) 2008 Optical Society of America.
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| 66. |
- Wosinski, Lech, et al.
(författare)
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Advanced silicon device technologies for optical interconnects
- 2012
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Ingår i: Optoelectronic Integrated Circuits XIV. - : SPIE - International Society for Optical Engineering. - 9780819489081 ; , s. 826506-
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Konferensbidrag (refereegranskat)abstract
- Silicon photonics is an emerging technology offering novel solutions in different areas requiring highly integrated communication systems for optical networking, sensing, bio-applications and computer interconnects. Silicon photonicsbased communication has many advantages over electric wires for multiprocessor and multicore macro-chip architectures including high bandwidth data transmission, high speed and low power consumption. Following the INTEL's concept to "siliconize" photonics, silicon device technologies should be able to solve the fabrication problems for six main building blocks for realization of optical interconnects: light generation, guiding of light including wavelength selectivity, light modulation for signal encoding, detection, low cost assembly including optical connecting of the devices to the real world and finally the electronic control systems.
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| 67. |
- Wosinski, Lech, et al.
(författare)
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Amorphous Silicon in Nanophotonic Technology
- 2007
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Konferensbidrag (refereegranskat)abstract
- Silicon-on-insulator nanowire waveguides appear to be the technology for next generation of super compact integrated devices. Due to a very high refractive index contrast and strong light confinement in the core, the waveguide bend radius can be reduced to a few micrometers and the size reduction of the functional integrated circuits can reach several orders of magnitude in comparison to standard integrated optics based on silica-on-silicon technology. Amorphous silicon is an interesting material allowing for more flexibility in nanowire structures. An array waveguide grating multi/demultiplexer that usually occupies several square centimetres in silica-on-silicon technology can be reduced to the size of 320 x 270 μm2.
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| 68. |
- Wosinski, Lech, et al.
(författare)
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Silicon- and plasmonics-based nanophotonics for telecom and interconnects
- 2012
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Ingår i: 2012 Asia Communications And Photonics Conference (ACP). ; , s. AW1A.3-
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Konferensbidrag (refereegranskat)abstract
- We presented a set of fabricated devices based on silicon nanowire waveguides in application to telecom and optical interconnects. New developments in form of hybrid plasmonic waveguides allowing for sub-wavelength light confinement are also included.
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| 69. |
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| 70. |
- Yu, Longhai, et al.
(författare)
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Graphene-based transparent flexible heat conductor for thermally tuning nanophotonic integrated devices
- 2014
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 105:25, s. 251104-
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Tidskriftsartikel (refereegranskat)abstract
- Graphene, a well-known two-dimensional sheet, has attracted strong interest for both fundamental studies and applications. Due to its high intrinsic thermal conductivity, graphene has many potential applications in thermal management, such as in heat spreaders and flexible heaters. In this paper, a graphene-based transparent flexible heat conductor for nanophotonic integrated devices is demonstrated. The graphene heat conductor is designed to deliver heat from a non-local traditional metal heater to nanophotonic integrated devices for realizing efficient thermal tuning. With the present graphene heat conductor, a thermally tuning silicon Mach-Zehnder interferometer and micro-disk have been realized with good performance in terms of heating efficiency and temporal response. This indicates that the present graphene-based transparent flexible heat conductor provides an efficient and beneficial heating method for thermally tuning nanophotonic integrated devices.
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