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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.
251

A Study of Gain-flattened L-Band EDFA

Tseng, Wen-Hung 27 June 2000 (has links)
ABSTRACT In this thesis, we investigate the amplification characteristics of gain-flattened L-band (1570-1600 nm) erbium-doped fiber amplifier (EDFA) by employing the 1480 nm bi-directional pumping configuration. L-Band EDFAs are attractive because the use of L-band and C-band (1530-1560 nm) EDFAs in parallel greatly expands the amplification wavelength region. We adjusted the length of erbium-doped fiber (EDF) to achieve the flat amplification characteristics in the 1573-1600 nm wavelength region without using gain equalizers. The L-band EDFA exhibited a signal gain of 23 dB with good uniformity (less than 1 dB) and a noise figure of 6.9 dB for a 1580 nm signal of 16-channel WDM system. We also used the simulation tools to investigate the characteristics of L-band EDFA with the same configuration. The simulation results quite agree with the experimental data.
252

Photocurrent and Electroabsorption Spectroscopy for Semiconductor Quantum Well Structures

Fan, Hsiang-Pin 10 July 2001 (has links)
In this thesis, we have setup the measurement systems for photocurrent and electro-absorption (Da) spectroscopy, and have investigated the optical characteristics of semiconductor quantum well structures in the long wavelength regime. The measured samples are of three epi-structures including a p-i-n laser structure of the symmetric multiple quantum wells (SMQWs), a p-i-n laser structure of the asymmetric multiple quantum wells (AMQWs), and n-i-n BRAQWETS structures. The samples are fabricated in mesa type photodiode structures for the measurements. From the Da spectrum of the n-i-n BRAQWETS structures, we observe a blue shift ~ 10nm of Da peak caused by band filling effect at +5V bias. Besides, a red shift ~ 2nm has been obtained at ¡V5V bias caused by the quantum-confined Stark effect. The photocurrent spectrum of the SMQWs shows an e1-hh1 absorption peak at hn=0.813eV (l=1.525mm) which matches the photoluminesce spectrum. The e1-hh1 transition has a red-shift ~ 38nm at ¡V5V bias for the SMQWs. For the AMQWs consisting of 5, 10, 15nm wells, we observe the e1-hh1 absorption peaks at 0.758eV (l=1.64mm), 0.772eV (l=1.6mm) and 0.797eV (l=1.55mm), respectively. As the AMQWs biased at ¡V5V, a red-shift ~ 25nm is obtained for the e1-hh1 transition corresponding to the 15nm-wide wells.
253

Optical Ultra-Wide-Band Pulse generation by Quantum Well-Waveguide device

Chou, Yi-fen 06 August 2008 (has links)
Ultra Wide Band (UWB) is a short-pulse electrical signal, which is widely used for short distant wireless communication due to its low path loss, good immunity to multipath propagation, and high data rate. The main target transmission area of UWB is within 10 meters. Using optical fiber as carrier can bust up the communication capacitance in long distance range because of high capacitance, low loss propagation, and TDM and WDM compatible properties of fiber. Thereby, the technique of UWB on fiber has become more and more important. In this work, a novel method using waveguide photodetector (WP) with short termination for interface of optical fiber and wireless is proposed and demonstrated. The structure is simple without employing any complicated frequency mixer, intermediate frequency, or complex systems. This work is divided into two parts: (1) generation of UWB electrical signals and (2) wavelength conversion of UWB through WP. In the former, a WP with short termination is used in the device. The photocurrent excited by short optical pulse is distributive generated through the waveguide, forming two opposite directions of electrical waves. By reflection on the short termination, the reversed phase of one electrical wave is added to another electrical wave through a delay line, forming a monocycle of UWB signal. By appropriate design on the length of waveguide, the band of 2-10GH is demonstrated, fitting the requirement of FCC (Federal Communications Commission). In the second part of this paper is the wavelength conversion of UWB. The active region of WG is multiple quantum wells (M.Q.W.), which is not only served as photo-absorption layer, but also can be used the electroabsorption material. By pumping M.Q.W.s with high optical power, the cross absorption properties can be applied for wavelength conversion. By pumping power of 12dBm, the wavelength-converted UWB signal is successfully demonstrated at range of 1545nm-1570nm. Using this method, the application of UWB on router of fiber optical network is expectable.
254

The Effects of Windshield and Car Body on the Hidden Automotive Antenna

Tang, Tzu-chun 15 July 2009 (has links)
In this thesis, we discuss the subject into four parts. Firstly, we introduce the telematics for automotive. Secondary, we study the effects of locations of the hidden antenna. Thirdly, we discuss the effects of the windshield to the hidden antenna as we place the antenna on the windshield, then, the window film is attached to the windshield. We conduct implementation and measurement to analyze the effect of the film to the antenna. Finally, we find that the antenna gain is degraded in certain receiving angle due to the car body as we place the antenna at the corner of the windshield. In order to improve this, we design an EBG structure and place it between the antenna and the car body. The simulation result indicates that the EBG structure not only improves the gain in certain receiving angles but also reduces the induced current intensity on the car body.
255

The history and development of the symphonic band

Resendes, Joseph M. January 2007 (has links)
Thesis (M.A.)--York University, 2007. Graduate Programme in Music. / Typescript. Includes bibliographical references (leaves 91-92). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004 & res_dat=xri:pqdiss & rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation & rft_dat=xri:pqdiss:MR32036.
256

Roy Harris' American symphony, 1938 a perspective on its historical significance and autogenetic elements with a performance of a reconstructed modern wind ensemble edtion /

Lamb, Brian, January 2001 (has links)
Thesis (D.M.A.)--University of North Texas, 2001. / Arrangement for band on p. 111-196. Includes bibliographical references (p. 203-206).
257

"BOZ" for jazz orchestra and vocal /

Gunduz, Esin. January 2009 (has links)
Thesis (M.A.)--Marshall University, 2009. / Title from document title page. Includes abstract. Document formatted into pages: contains 29 p.
258

Symphony no. 2 for band

Archer, Kimberly K. 07 July 2015 (has links)
Symphony no. 2 is a three-movement work for band. Each movement is dedicated to a pivotal figure in my development as a composer. The first movement is a march/scherzo based on octatonic collections, the second movement is a passacaglia modeled after the style of Philip Glass, and the third movement is a theme and variations written in my own personal style. Additionally, all three movements contain references to the hymn "Blessed Assurance" in gradually more obvious forms as the work progresses, although only the third movement includes an outright statement of the tune. This treatise consists of the full score for the symphony, followed by a discussion of the programmatic, formal, harmonic, and motivic elements of the music. / text
259

David Maslanka's Symphony No. 4: a conductor's analysis with performance considerations

Bolstad, Stephen Paul 28 August 2008 (has links)
Not available / text
260

Near-infrared narrow-band imaging of gold/silica nanoshells in tumors

Puvanakrishnan, Priyaveena 03 September 2009 (has links)
Gold nanoshells (GNS) are a new class of nanoparticles that can be optically tuned to scatter or absorb light from the near-ultraviolet to near-infrared (NIR) region by varying the core (dielectric silica) /shell (gold) ratio. In addition to spectral tunability, GNS are inert and bioconjugatable making them potential labels for in vivo imaging and therapy of tumors. We report the use of GNS as exogenous contrast agents for enhanced visualization of tumors using narrow band imaging (NBI). NBI takes advantage of the strong NIR absorption of GNS to distinguish between blood and nanoshells in the tumor by imaging in narrow wavelength bands in the visible and NIR, respectively. Using tissue-simulating phantoms, we determined the optimum wavelengths to enhance contrast between blood and GNS. We then used the optimum wavelengths for ex-vivo imaging of tumors extracted from human colon cancer xenograft bearing mice injected with GNS. Systemically delivered GNS accumulated passively in tumor xenografts by enhanced permeability and retention (EPR) effect. Ex-Vivo NBI of tumor xenografts demonstrated tumor specific heterogeneous distribution of GNS with a clear distinction from the tumor vasculature. The results of the present study demonstrate the feasibility of using GNS as contrast agents to visualize tumor tissues using NBI technique. / text

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