<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="static/style.xsl"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-09-19T10:45:43Z</responseDate><request verb="GetRecord" identifier="oai:dspace.mit.edu:1721.1/42115" metadataPrefix="dim">https://dspace.mit.edu/server/oai/request</request><GetRecord><record><header><identifier>oai:dspace.mit.edu:1721.1/42115</identifier><datestamp>2022-01-13T07:54:29Z</datestamp><setSpec>com_1721.1_7582</setSpec><setSpec>com_1721.1_7581</setSpec><setSpec>col_1721.1_131023</setSpec></header><metadata><dim:dim xmlns:dim="http://www.dspace.org/xmlns/dspace/dim" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:doc="http://www.lyncode.com/xoai" xsi:schemaLocation="http://www.dspace.org/xmlns/dspace/dim http://www.dspace.org/schema/dim.xsd">
   <dim:field mdschema="dc" element="contributor" qualifier="advisor" lang="en_US">Franco N.C. Wong.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="author" lang="en_US">Venkatraman, Dheera</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="other" lang="en_US">Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="department">Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="accessioned">2008-09-03T14:38:19Z</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="available">2008-09-03T14:38:19Z</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="copyright" lang="en_US">2007</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="issued" lang="en_US">2007</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="uri">http://hdl.handle.net/1721.1/42115</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="oclc" lang="en_US">226372606</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Includes bibliographical references (p. 50-52).</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="abstract" lang="en_US">Two separate projects were undertaken to improve technology for entangled photon sources, useful for quantum optics. In one project, a pulsed, mode-locked erbium-doped fiber laser, designed to be used as a seed laser for a 390 nm source, was built using polarization-maintaining components to address polarization drift. The fiber laser operated at a center wavelength of 1560.0 nm with an output power of 1 to 2.5 mW, and mode-locked with a repetition rate of 31.1 MHz. The laser also exhibited bandwidth tunability from 0.045 to 0.095 nm, as a function of the input pump power. A commercial 5 W erbium-doped fiber amplifier and a second harmonic generation crystal were used to obtain pulses at 780 nm with an average power of 3 W. The next second harmonic generation stage, for generating the desired 390 nm output, remains to be built. In the second project, we tried to optimize the coupling efficiency of light generated from spontaneous parametric downconversion (SPDC) into single-mode optical fibers, which are useful for transporting entangled photons. Using a setup with a tunable 532 nm pump waist in a nonlinear crystal, we achieved an effective coupling efficiency of 48.8% of the 797 nm signal light into a single-mode fiber, higher than previously obtained in the laboratory. Efficient single-mode operation of SPDC would enable the construction of a high-flux fiber-coupled source of nondegenerate entangled photons at 797 nm and 1600 nm.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="statementofresponsibility" lang="en_US">by Dheera Venkatraman.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="degree" lang="en_US">M.Eng.</dim:field>
   <dim:field mdschema="dc" element="format" qualifier="extent" lang="en_US">52 p.</dim:field>
   <dim:field mdschema="dc" element="language" qualifier="iso" lang="en_US">eng</dim:field>
   <dim:field mdschema="dc" element="publisher" lang="en_US">Massachusetts Institute of Technology</dim:field>
   <dim:field mdschema="dc" element="rights" lang="en_US">M.I.T. theses are protected by 
copyright. They may be viewed from this source for any purpose, but 
reproduction or distribution in any format is prohibited without written 
permission. See provided URL for inquiries about permission.</dim:field>
   <dim:field mdschema="dc" element="rights" qualifier="uri" lang="en_US">http://dspace.mit.edu/handle/1721.1/7582</dim:field>
   <dim:field mdschema="dc" element="subject" lang="en_US">Electrical Engineering and Computer Science.</dim:field>
   <dim:field mdschema="dc" element="title" lang="en_US">Tools for quantum optics : pulsed polarization-maintaining Er-doped fiber laser and spatial mode manipulation in spontaneous parametric downconversion</dim:field>
   <dim:field mdschema="dc" element="title" qualifier="alternative" lang="en_US">Picosecond polarization-maintaining Er-doped fiber laser for quantum optics and the construction of a high-flux non-degenerate entangled photon pair source</dim:field>
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   	&lt;Title>Tools for quantum optics : pulsed polarization-maintaining Er-doped fiber laser and spatial mode manipulation in spontaneous parametric downconversion&lt;/Title>
   	&lt;Subtitle>Picosecond polarization-maintaining Er-doped fiber laser for quantum optics and the construction of a high-flux non-degenerate entangled photon pair source&lt;/Subtitle>
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   	&lt;PublicationDate>2007&lt;/PublicationDate>
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    &lt;Keyword>Electrical Engineering and Computer Science.&lt;/Keyword>
   	&lt;Abstract>Two separate projects were undertaken to improve technology for entangled photon sources, useful for quantum optics. In one project, a pulsed, mode-locked erbium-doped fiber laser, designed to be used as a seed laser for a 390 nm source, was built using polarization-maintaining components to address polarization drift. The fiber laser operated at a center wavelength of 1560.0 nm with an output power of 1 to 2.5 mW, and mode-locked with a repetition rate of 31.1 MHz. The laser also exhibited bandwidth tunability from 0.045 to 0.095 nm, as a function of the input pump power. A commercial 5 W erbium-doped fiber amplifier and a second harmonic generation crystal were used to obtain pulses at 780 nm with an average power of 3 W. The next second harmonic generation stage, for generating the desired 390 nm output, remains to be built. In the second project, we tried to optimize the coupling efficiency of light generated from spontaneous parametric downconversion (SPDC) into single-mode optical fibers, which are useful for transporting entangled photons. Using a setup with a tunable 532 nm pump waist in a nonlinear crystal, we achieved an effective coupling efficiency of 48.8% of the 797 nm signal light into a single-mode fiber, higher than previously obtained in the laboratory. Efficient single-mode operation of SPDC would enable the construction of a high-flux fiber-coupled source of nondegenerate entangled photons at 797 nm and 1600 nm.&lt;/Abstract>
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