| 1. |
- Broeke, Ronald G., et al.
(författare)
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Optical-CDMA in InP
- 2007
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Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 1077-260X .- 1558-4542. ; 13:5, s. 1497-1507
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes the InP platforms for photonic integration and the development on these platforms of an optical code division multiple access (O-CDMA) system for local area networks. We demonstrate three building blocks of this system: an optical pulse source, an encoder/decoder pair, and a threshold detector. The optical pulse source consists of an integrated colliding pulse-mode laser with nearly transform-limited 10 Gb/s pulses and optical injection locking to an external clock for synchronization. The encoder/decoder pair is based on arrayed waveguide gratings. Bit-error-rate measurements involving six users at 10 Gb/s showed error-free transmission, while O-CDMA codes were calibrated using frequency resolved optical gating. For threshold detection after the decoder, we compared two Mach-Zehnder interferometer (MZI)-based optical thresholding schemes and present results on a new type of electroabsorber-based MZI.
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| 2. |
- Chen, Biao, et al.
(författare)
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Efficient and fine scheduling algorithm for bandwidth allocation in Ethernet passive optical networks
- 2006
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Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - 1077-260X .- 1558-4542. ; 12:4, s. 653-660
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Tidskriftsartikel (refereegranskat)abstract
- A novel fine scheduling algorithm is introduced for upstream bandwidth allocation in an Ethernet-based passive optical network. This scheduling algorithm consists of an inter optical network unit (ONU) scheduler at the optical line terminal (OLT) and an intra-ONU scheduler at each ONU. In the inter-ONU scheduling, a novel GATE/REPORT approach is introduced to eliminate the unused remainders without transmission delay and maximize the utilization of bandwidth. Our novel intra-ONU scheduler gives fair bandwidth allocation to the queues of different priorities for each user in a hierarchical and decentralized way. Numerical results have shown that our overall scheduling algorithm can fulfill various requirements of delay and throughput for the transmission of multimedia traffic for each end user..
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| 3. |
- Dai, Daoxin, et al.
(författare)
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Elimination of multimode effects in a silicon-on-insulator etched diffraction grating demultiplexer with bi-level taper structure
- 2005
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Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - 1077-260X .- 1558-4542. ; 11:2, s. 439-443
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Tidskriftsartikel (refereegranskat)abstract
- Multimode effects in the free propagation region (FPR) of an etched diffraction grating (EDG) demultiplexer based on silicon-on-insulator are analyzed. The insertion loss and the crosstalk increase due to these undesired multimode effects. A bi-level taper structure between the FPR and the input/output waveguides is proposed. It is shown that such a taper structure can reduce the multimode effects to an almost negligible level. At the same time, the 3-dB passband width is enlarged by increasing the rib width. No additional fabrication process is needed for an EDG with such a design.
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| 4. |
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| 5. |
- Ji, C., et al.
(författare)
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Monolithically integrated InP-based photonic chip development for O-CDMA systems
- 2005
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Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 1077-260X .- 1558-4542. ; 11:1, s. 66-77
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Tidskriftsartikel (refereegranskat)abstract
- This paper discusses photonic integration efforts toward developing an InP-based inonolithically integrated photonic chip for optical code-division multiple-access (O-CDMA) system applications. The chip design includes the colliding pulsed mode (CPM) locked laser, the. Mach-Zehnder interferometer-based threshold detector (MZI), and the monolithic O-CDMA encoder/decoder chip based on array-waveguide-gratings and phase modulator arrays. The compact 4 x I cm monolithic chip can replace a complex and large O-CDMA setup based on bulk optics. The integration technique involves active-passive integration using dry etching, metal organic chemical vapor deposition growth, and lateral hydride vapor phase epitaxy regrowth technologies. The fabricated CPM showed stable 1.54 ps modelocked laser output, the MZI showed excellent O-CDMA threshold detection, and the O-CDMA encoder showed Walsh-code O-CDMA, encoding. Further, the fabricated devices showed excellent planarity, which accelerate our progress toward monolithic integration of O-CDMA systems.
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| 6. |
- Lindberg, H., et al.
(författare)
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Thermal management of optically pumped long-wavelength InP-based semiconductor disk lasers
- 2005
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Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - 1077-260X .- 1558-4542. ; 11:5, s. 1126-1134
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Tidskriftsartikel (refereegranskat)abstract
- We have developed a numerical model for investigating material heating and its effects on the performance of optically pumped InP-based long-wavelength semiconductor disk lasers. Material heating and optical wavefront distortion due to thermal lensing are analyzed, and different approaches to reduce the intrinsic material heating are investigated numerically and experimentally. The results obtained indicate that material heating is significant in such lasers due to the poor thermal properties of the InP-based epitaxial layers of the gain chip. Substrate removal is shown to be an insufficient method to reduce the material heating; instead, crystalline heat spreaders bonded to the gain chip surface provide a convenient way to reduce the thermal impedance. Important parameters for such heat spreaders are a high thermal conductivity and a low thermooptic coefficient (dn / dT). With the use of a synthetic diamond heat spreader, a maximum pump limited output power of 780 mW in a near diffraction limited beam (M-2 < 1.2) was demonstrated at - 33 degrees C and 100 mW at room temperature.
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| 7. |
- Liu, Fangfei, et al.
(författare)
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Optically Tunable Delay Line in Silicon Microring Resonator Based on Thermal Nonlinear Effect
- 2008
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Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - 1077-260X .- 1558-4542. ; 14:3, s. 706-712
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Tidskriftsartikel (refereegranskat)abstract
- We experimentally demonstrate optically tunable delay fine in a silicon microring resonator with a 20-mu m radius. The delay-tuning mechanism is based on the red shift of the resonance induced by thermal nonlinear effect. We investigate the delay performance of three modulation formats-non-return-to-zero (NRZ), return-to-zero (RZ), and differential phase-shift keying (DPSK) signals at different data rates. Tunable delay is achieved by controlling the power of the continuous-wave (CW) pump with very low tuning threshold, which could be used in microring-resonator-based slow-light structure.
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| 8. |
- Lynch, S.A., et al.
(författare)
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Toward silicon-based lasers for terahertz sources
- 2006
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Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - 1077-260X .- 1558-4542. ; 12:6, s. 1570-1577
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Tidskriftsartikel (refereegranskat)abstract
- Producing an electrically pumped silicon-based laser at terahertz frequencies is gaining increased attention these days. This paper reviews the recent advances in the search for a silicon-based terahertz laser. Topics covered include resonant tunneling in p-type Si/SiGe, terahertz intersubband electroluminescence from quantum cascade structures, intersubband lifetime measurements in Si/SiGe quantum wells, enhanced optical guiding using buried suicide layers, and the potential for exploiting common impurity dopants in silicon such as boron and phosphorus to realize a terahertz laser. © 2006 IEEE.
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| 9. |
- Peter, Yves-Alain, et al.
(författare)
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Introduction to the Issue on Nanophotonics and Optical MEMS
- 2009
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Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 1077-260X .- 1558-4542. ; 15:5, s. 1307-1309
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 10. |
- Qian, J., et al.
(författare)
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Quantum-Dots-Doped ORMOSIL Nanoparticles as Optical Probes for Total Internal Reflection Fluorescence Imaging of Cancer Cells
- 2009
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Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 1077-260X .- 1558-4542. ; 15:5, s. 1374-1379
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Tidskriftsartikel (refereegranskat)abstract
- We report the novel use of organically modified silica (ORMOSIL) nanoparticles to encapsulate hydrophobic quantum dots (QDs), thus making them hydrophilic and yet maintaining stable optical properties. QDs are resistant to photobleaching, and the cationic charge on the surfaces of the ORMOSIL nanoparticles can facilitate them being uptaken at the cell substrate regions. An objective-lens-based total internal reflection fluorescence (TIRF) microscope is used to observe the staining and dynamics of HeLa cancer cells, which have been targeted by the synthesized QD-doped ORMOSIL nanoparticles. Since the same microscope objective is used for launching the incident light beam and the collection lens, the observation and manipulation of live samples under a TIRF microscope is therefore much easier than that in the case of using the conventional prism-based TIRF setup. The present nanoparticle-assisted approach has made TIRF imaging a much more powerful tool for real-time monitoring of intracellular biological metabolic activities.
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