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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Dynamik und Absorptionsempfindlichkeit von vielmodigen Faser- und Glas-Lasern

Hünkemeier, Jörg. January 2001 (has links) (PDF)
Hamburg, Univ., Diss., 2001. / Computerdatei im Fernzugriff.
2

Dynamik und Absorptionsempfindlichkeit von vielmodigen Faser- und Glas-Lasern

Hünkemeier, Jörg. January 2001 (has links) (PDF)
Hamburg, Univ., Diss., 2001. / Computerdatei im Fernzugriff.
3

Dynamik und Absorptionsempfindlichkeit von vielmodigen Faser- und Glas-Lasern

Hünkemeier, Jörg. January 2001 (has links) (PDF)
Hamburg, Universiẗat, Diss., 2001.
4

IMPACT STUDY OF MULTIMODE FIBRE TAPER IN MODAL NOISE UNDER RESTRICTED OFFSET LAUNCH CONDITIONS

Qian, Chen 15 November 2007 (has links)
Delivering high bandwidth to the individual household or small business is currently a major bottleneck in the high speed network, a problem referred to as the last mile issue. Multimode fibre is widely deployed in the last mile for cost reasons. Recently, the tremendous high-speed data transport potential of multimode fibre has been demonstrated by utilizing offset launch techniques and a laser source. However, modal noise, caused by interference among the various propagating modes of a multimode fibre in the presence of mode selective loss, is a significant roblem when a laser source is employed. This thesis investigates several aspects of modal noise for what we believe to be the first time. By utilizing single mode fibre launching, modal noise is measured at different transverse offset launching positions with both continuous wave and pulse waveform input at several different fibre lengths. Modal noise is also measured for both waveforms in conjunction with a multimode optical fibre taper in an “in line” configuration, and timing jitter is investigated for the case of pulse waveform input. Performance improvements are found in some offset positions with the fibre taper in line. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2007-11-15 09:37:44.887
5

An investigation of ultra-high capacity MMF links

Kourtessis, Pandelis January 2003 (has links)
No description available.
6

Telemetry Re-Radiation System

Cook, Paul, Natale, Louis 10 1900 (has links)
ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, California / Enclosed weapon bays on modern aircraft interfere with prelaunch, Flight Termination System verification during training test launches. Range safety personnel need to verify the functionality of the flight termination system prior to missile launch. The missile telemetry RF is highly attenuated when the aircraft missile bay doors are closed, limiting the range for which the aircraft can fly during training flights. Teletronics Technology Corporation and Lockheed Martin designed a system to provide telemetry data for these aircraft. The system re-radiates the telemetry from the missiles with the weapon bay doors closed. This paper describes the design considerations for this flexible system that accommodates multiple weapon systems in multiple weapon bay configurations.
7

Energy efficient scheduling techniques for real-time embedded systems

Prathipati, Rajesh Babu 30 September 2004 (has links)
Battery-powered portable embedded systems have been widely used in many applications. These embedded systems have to concurrently perform a multitude of complex tasks under stringent time constraints. As these systems become more complex and incorporate more functionality, they became more power-hungry. Thus, reducing power consumption and extending battery lifespan while guaranteeing the timing constraints has became a critical aspect in designing such systems. This gives rise to three aspects of research: (i) Guaranteeing the execution of the hard real-time tasks by their deadlines, (ii) Determining the minimum voltage under which each task can be executed, and (iii) Techniques to take advantage of run-time variations in the execution times of tasks. In this research, we present techniques that address the above aspects in single and multi processor embedded systems. We study the performance of the proposed techniques on various benchmarks in terms of energy savings.
8

Applying multimode interference couplers in ring resonators

Tsai, Yi-Lin 02 August 2009 (has links)
This study uses vertical mirror optical waveguide reflector and bending waveguide to fabricate semiconductor ring resonators. By using multimode interference couplers with specific width and length that generate distinctive energy distribution to achieve the power splitting of 85:15. We integrate vertically deep etching turning mirror to reflect optical mode, and reduce the component size to 37.6%. In fabrication process, this study applies multiple wet etching technique to form the waveguide structure. First, we use wet etching technique to etch ridge waveguide and turning mirror, and then perform deep etching in the periphery of bending and turning region to reduce the bending loss. Finally, the etching mask is lifted off, and the wafer is polished and sliced for measurement. After measuring the signal, we can compute waveguide loss by Fabry-perot resonant situation. The waveguide loss is 59.6dB/cm. Power splitting of 90:10 is achieved. The free spectral range (FSR) is 72GHz for the ring resonators.
9

High speed fibre-optic datacommunication systems

Lutz, Raddatz January 1998 (has links)
No description available.
10

Multimode Optomechanical Systems and Phononic Networks

Kuzyk, Mark 11 January 2019 (has links)
An optomechanical system consists of an optical cavity mode coupled to a mode of a mechanical oscillator. Depending on the configuration of the system, the optomechanical interaction can be used to drive or cool the mechanical mode, coherently swap the optical and mechanical states, or create entanglement. A multimode optomechanical system consists of many optical (mechanical) modes coupled to a mechanical (optical) mode. With the tools of the optomechanical interaction, multimode optomechanical systems provide a rich platform to study new physics and technologies. A central challenge in optomechanical systems is to mitigate the effects of the thermal environment, which remains significant even at cryogenic temperatures, for mechanical oscillators typically used in optomechanical systems. The central theme of this thesis is to study how the properties of multimode optomechanical systems can be used for such mitigation of thermal noise. The most straightforward extension of an optomechanical system to a multimode system is to have a single optical mode couple to two mechanical modes, or a single mechanical mode couple to two optical modes. In this thesis, we study both types of multimode system. In each case, we study the formation of a dark mode, an eigenstate of the three-mode system that is of particular interest. When the system is in a dark state, the two modes of similar character (optical or mechanical) interact with each other through the mode of dissimilar character, but due to interference, the interaction becomes decoupled from the properties of the dissimilar mode. Another interesting application of the three-mode system is two-mode optical entanglement, generated through mechanical motion. Such entanglement tends to be sensitive to thermal noise. We propose a new method for generating two-mode optical entanglement in the three-mode system that is robust against the thermal environment of the mechanical mode. Finally, we propose a novel, scalable architecture for a quantum computer. The architecture makes use of the concepts developed earlier in the thesis, and applies them to a system that on the surface looks quite different from the standard optomechanical system, but is formally equivalent. This dissertation includes previously published and unpublished coauthored material.

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