| 1. |
- Lobov, Gleb, et al.
(författare)
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Electro-optical effects of high aspect ratio P3HT nanofibers colloid in polymer micro-fluid cells
- 2017
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Ingår i: Optics Letters. - : OSA Publishing. - 0146-9592 .- 1539-4794. ; 42:11, s. 2157-2160
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Tidskriftsartikel (refereegranskat)abstract
- This Letter reports the electro-optical (EO) effect of Poly(3-hexylthiophene-2,5-diyl) (P3HT) nanofibers colloid in a polymer micro-fluidic EO cell. P3HT nanofibers are high aspect ratio semiconducting nanostructures, and can be collectively aligned by an external alternating electric field. Optical transmission modulated by the electric field is a manifestation of the electro-optical effect due to high inner crystallinity of P3HT nanofibers. According to our results, the degree of alignment reaches a maximum at 0.6 V/μm of electric field strength, implying a big polarizability value due to geometry and electrical properties of P3HT nanofibers. We believe that one-dimensional crystalline organic nanostructures have a large potential in EO devices due to their significant anisotropy, wide variety of properties, low actuation voltages, and opportunity to be tailored via adjustment of the fabrication process.
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| 2. |
- Lobov, Gleb
(författare)
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Electro-optical properties of one-dimensional organic crystals
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The recent development of photonics and applications puts new challenges for systems using emission, transmission and modulation of light. For these reasons, novel optical materials attract a special interest for their enabling properties for novel technologies.In this work, we performed the research on fundamental properties and the possibility of implementation of electro-optical response of Poly-3-hexylthiophene-2,5-diyl (P3HT) nanofibers, which belong to the class of organic semiconductor crystalline materials. Our research demonstrated that an external electric field allows controlling the orientation of nanofibers dispersed in a solution by changing the electrical properties of P3HT crystals. This method was used to introduce a collective alignment of P3HT nanofibers and to impact the optical properties of the colloid. The spectroscopic and polarization measurements show that P3HT nanofibers possess optical anisotropy in a wide range of visible spectrum. This property combined with the ability to manipulate the orientation of nanofibers dynamically, was used for direct phase and intensity modulation of transmitted light. Along with these investigations, several engineering and technology tasks were solved. We have designed the transverse electro-optical cell using all-optical-fiber approach, as well as the longitudinal electro-optical cell was fabricated using a novel polymer molding technique.The obtained research results demonstrate the potential of P3HT crystalline nanofibers as a material class of large niche of applications, not only limited to photovoltaics but also being implemented in electro-optical systems to control light polarization and propagation.
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| 3. |
- Lou, Fei, et al.
(författare)
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Transmission characteristics of a novel grating assisted microring
- 2011
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Ingår i: 2011 Asia Communications and Photonics Conference and Exhibition, ACP 2011. - Washington, D.C. : IEEE Computer Society. - 9780819489616 ; , s. 83080A-
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Konferensbidrag (refereegranskat)abstract
- We propose a new type of grating-assisted microring (GAMR) structure with Bragg gratings placed on microring's arms. Two Fabry-Perot resonances interact with microring resonance, resulting in GAMR's unique amplitude and phase spectra. The structure's characteristics are analytically studied using coupled mode theory and numerically verified by 2D-FDTD. With proper cavity lengths, GAMR exhibits an electromagnetically induced transparency (EIT)-like spectrum. The ultra-narrow resonance can be used for sensing, modulation, and other applications.
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| 4. |
- Sun, Xu, 1987-, et al.
(författare)
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Double-Slot Hybrid Plasmonic Ring Resonator Used for Optical Sensors and Modulators
- 2015
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Ingår i: Photonics. - Basel, Switzerland : MDPI AG. - 2304-6732. ; 2:4, s. 1116-1130
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Tidskriftsartikel (refereegranskat)abstract
- An ultra-high sensitivity double-slot hybrid plasmonic (DSHP) ring resonator, used for optical sensors and modulators, is developed. Due to high index contrast, as well as plasmonic enhancement, a considerable part of the optical energy is concentrated in the narrow slots between Si and plasmonic materials (silver is used in this paper), which leads to high sensitivity to the infiltrating materials. By partial opening of the outer plasmonic circular sheet of the DSHP ring, a conventional side-coupled silicon on insulator (SOI) bus waveguide can be used. Experimental results demonstrate ultra-high sensitivity (687.5 nm/RIU) of the developed DSHP ring resonator, which is about five-times higher than for the conventional Si ring with the same geometry. Further discussions show that a very low detection limit (5.37 × 10−6 RIU) can be achieved after loaded Q factor modifications. In addition, the plasmonic metal structures offer also the way to process optical and electronic signals along the same hybrid plasmonic circuits with small capacitance (~0.275 fF) and large electric field, which leads to possible applications in compact high-efficiency electro-optic modulators, where no extra electrodes for electronic signals are required
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| 5. |
- Sun, Xu, 1987-, et al.
(författare)
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Hollow Hybrid Plasmonic Waveguide Used for Electro-optic Phase Modulation
- 2016
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Ingår i: Optics InfoBase Conference Papers. - : Optical Society of America. ; , s. AF3F.2-
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Konferensbidrag (refereegranskat)abstract
- An electro-optic polymer-based hollow hybrid plasmonic phase modulator has beenproposed. Estimating from our preliminary experimental results, related to a hollow HP liquidsensor, the proposed device shows unique advantages in high speed modulation applications.
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| 6. |
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| 7. |
- Tang, Yongbo, et al.
(författare)
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High efficiency nonuniform grating coupler by utilizing the lag effect in the dry etching process
- 2010
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Ingår i: Optics InfoBase Conference Papers. - Washington, D.C. : Optical Society of America (OSA). - 9781557528841
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Konferensbidrag (refereegranskat)abstract
- Utilizing the lag effect in dry etching, a nonuniform silicon-on-insulator grating coupler is designed and fabricated. Over 80% (>-1dB) coupling efficiency is theoretically obtained and experimental coupling efficiency of 55% is achieved for TE polarization.
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| 8. |
- Thylén, Lars, et al.
(författare)
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Nanophotonics for Low-Power Switches
- 2013
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Ingår i: Optical FiberTelecommunications VIA. - Oxford : Elsevier. - 9780123969583 - 9780123972354 ; , s. 205-241
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter treats several approaches for employing nanophotonics or near-nanophotonics concepts to create low-power switches. The partly interrelated issues of low power dissipation and small device footprint are elucidated and figures of merit for switches formulated. Both optically and electronically controlled optical switches are treated and the crucial role of material development emphasized, illustrated by several examples, including both theoretical analysis of switch concepts and experimentally realized switches. Thus, electronically controlled switches based on hybrid, metamaterial and nanoparticle plasmonics, electrooptic polymers as well as switches based on silicon and photonic crystals are discussed. The all-optical switches focus on third-order nonlinear effects and carrier-induced refractive-index changes in III-V materials, as well as on emerging concepts of near-field-coupled quantum-dot switches. A brief comparison to electronic switches is done.
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| 9. |
- Wang, Zhechao, et al.
(författare)
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Experimental realization of a low-loss nano-scale Si hybrid plasmonic waveguide
- 2011
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Ingår i: Optics InfoBase Conference Papers. - Washington : Optical Society of America. - 9781557529060
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Konferensbidrag (refereegranskat)abstract
- A novel hybrid plasmonic waveguide with nano-scale confinement, consisting of a metal layer separated from a SOI nano-rib by a thin silica layer has been realized. The loss of 0.01dB/μm allows for ultra-high density photonic integration.
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| 10. |
- Wang, Zhechao, et al.
(författare)
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InP lateral overgrowth technology for silicon photonics
- 2010
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Ingår i: Optics InfoBase Conference Papers. - : Optical Society of America (OSA).
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Konferensbidrag (refereegranskat)abstract
- Epitaxial Lateral Overgrowth has been proposed as a key technology of a novel hybrid integration platform for active silicon photonic components. By fabricating silicon oxide mask on top of a thin InP seed layer, we can use the so called defect necking effect to filter out the threading dislocations propagating from the seed layer. By optimizing the process, thin dislocation free InP layers have been successfully obtained on top of silicon wafer. The obtained characterization results show that the grown InP layer has very high quality, which can be used as the base for further process of active photonic components on top of silicon.
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| 11. |
- Wang, Zhechao, et al.
(författare)
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InP Lateral Overgrowth Technology for Silicon Photonics
- 2011
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Ingår i: Optoelectronic Materials And Devices V. - : SPIE-INT SOC OPTICAL ENGINEERING.
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Konferensbidrag (refereegranskat)abstract
- Epitaxial Lateral Overgrowth has been proposed as a key technology of a novel hybrid integration platform for active silicon photonic components. By fabricating silicon oxide mask on top of a thin InP seed layer, we can use the so called defect necking effect to filter out the threading dislocations propagating from the seed layer. By optimizing the process, thin dislocation free InP layers have been successfully obtained on top of silicon wafer. The obtained characterization results show that the grown InP layer has very high quality, which can be used as the base for further process of active photonic components on top of silicon.
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| 12. |
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| 13. |
- Wosinski, Lech, 1951-, et al.
(författare)
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Silicon- and plasmonics-based nanophotonics for computer interconnects and sensing
- 2016
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Ingår i: 2016 Proceedings European Conference on Integrated Optics.
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Konferensbidrag (refereegranskat)abstract
- The talk gives an overview of our recent activities and achievements in the area ofsilicon nanophotonics technology and implementation of plasmonic structures forguiding and controlling light in applications to computer interconnects and sensing.The move from copper wiring to optical interfaces is approaching inter- and intra-chipcommunication as well as lab-on-a-chip solutions for biosensing.
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| 14. |
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| 15. |
- Wosinski, Lech, 1951-
(författare)
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Technology for photonic components in silica/silicon material structure
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The main objectives of this thesis were to develop a lowtemperature PECVD process suitable for optoelectronicintegration, and to optimize silica glass composition forUV-induced modifications of a refractive index in PECVDfabricated planar devices. The most important achievement isthe successful development of a low temperature silicadeposition, which for the first time makes it is possible tofabricate good quality low loss integrated components whilekeeping the temperature below 250oC during the entirefabrication process. Two strong absorption peaks thatappear at1.5 mm communication window due to N-H and Si-H bonds have beencompletely eliminated by process optimization. This openspossibilities for monolithic integration with other,temperature sensitive devices, such as semiconductor lasers anddetectors, or polymer-based structures on the common siliconplatform. PECVD technology for low loss amorphous silicon inapplication to SiO2/Si based photonic crystal structures hasbeen also optimized to remove hydrogen incorporated during thedeposition process, responsible for the porosity of thedeposited material and creation of similar to silica absorptionbands.Change of the refractive index of germanium doped silicaunder UV irradiation is commonly used for fabrication of UVinduced fiber Bragg gratings. Here we describe our achievementsin fabrication of fiber Bragg gratings and their application todistributed sensor systems. Recently we have built up a laserlab for UV treatment in application to planar technology. Wehave demonstrated the high photosensitivity of PECVD depositedGe-doped glasses (not thermally annealed) even without hydrogenloading, leading to a record transmission suppression of 47dBin a Bragg grating photoinduced in a straight buried channelwaveguide. We have also used a UV induced refractive indexchange to introduce other device modifications or functions,such as phase shift, wavelength trimming and control ofpolarization birefringence.The developed low temperature technology and the UVprocessing form a unique technology platform for development ofnovel integrated functional devices for optical communicationsystems.A substantial part of the thesis has been devoted tostudying different plasma deposition parameters and theirinfluence on the optical characteristics of fabricatedwaveguides to find the processing window giving the besttrade-off between the deposition rate,chamber temperatureduring the process, optical losses and presence of absorptionbands within the interesting wavelength range. The optimalconditions identified in this study are low pressure (300-400mTorr), high dilution of silane in nitrous oxide and high totalflow (2000 sccm), low frequency (380 KHz) RF source and high RFpower levels (800-1000 W).The thesis provides better understanding of the plasmareactions during the deposition process. RF Power is the keyparameter for increasing the rate of surface processes so as toaccommodate each atomic layer in the lowest energy statepossible. All the process conditions which favor a moreenergetic ion bombardment (i.e. low pressure, low frequency andhigh power) improve the quality of the material, making it moredense and similar to thermal oxide, but after a certain pointthe positive trend with increasing power saturates. As theenergy of the incoming ion increases, a competing effect setsin at the surface: ion induced damage and resputtering.Finally, the developed technologies were applied for thefabrication of some test and new concept devices for opticalcommunication systems including multimode interference (MMI)-based couplers/splitters, state-of-the-art arrayed waveguidegrating-based multi/ demultiplexers, the first Bragg gratingassisted MMI-based add-drop multiplexer, as well as moreresearch oriented devices such as a Mach-Zehnder switch basedon silica poling and a Photonic Crystal-based coupler.Keywords:silica-on-silicon technology, PECVD, plasmadeposition, photonic integrated circuits, planar waveguidedevices, UV Bragg gratings, photosensitivity, arrayed waveguidegratings, multimode interference couplers, add-dropmultiplexers.
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| 16. |
- Wosinski, Lech, 1951-, et al.
(författare)
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Technology of Hybrid Plasmonic Devices for Optical Bio-Sensing
- 2016
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Ingår i: 2016 18th International Conference on Transparent Optical Networks (ICTON). - : IEEE Computer Society. - 9781509014675
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Konferensbidrag (refereegranskat)abstract
- Hybrid plasmonics can provide a technology solution for lab-on-a-chip applications with nano-scale waveguiding and subwavelength light confinement, keeping the propagation loss on an acceptable level. In this talk we will present some designed and fabricated devices in application to bio-sensing, based on single-slot and double-slot hybrid plasmonic resonant structures on silicon platform that can be integrated to obtain a multi-sensor array on a single chip.
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| 17. |
- Wu, H., et al.
(författare)
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Ultracompact on-chip photothermal power monitor based on silicon hybrid plasmonic waveguides
- 2017
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Ingår i: Nanophotonics. - : Walter de Gruyter GmbH. - 2192-8614. ; 6:5, s. 1121-1131
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Tidskriftsartikel (refereegranskat)abstract
- We propose and demonstrate an ultracompact on-chip photothermal power monitor based on a silicon hybrid plasmonic waveguide (HPWG), which consists of a metal strip, a silicon core, and a silicon oxide (SiO2) insulator layer between them. When light injected to an HPWG is absorbed by the metal strip, the temperature increases and the resistance of the metal strip changes accordingly due to the photothermal and thermal resistance effects of the metal. Therefore, the optical power variation can be monitored by measuring the resistance of the metal strip on the HPWG. To obtain the electrical signal for the resistance measurement conveniently, a Wheatstone bridge circuit is monolithically integrated with the HPWG on the same chip. As the HPWG has nanoscale light confinement, the present power monitor is as short as ~3 μm, which is the smallest photothermal power monitor reported until now. The compactness helps to improve the thermal efficiency and the response speed. For the present power monitor fabricated with simple fabrication processes, the measured responsivity is as high as about 17.7 mV/mW at a bias voltage of 2 V and the power dynamic range is as large as 35 dB.
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