2026-09-19T21:09:47Zhttps://dspace.mit.edu/server/oai/requestoai:dspace.mit.edu:1721.1/346472026-06-11T12:44:50Zcom_1721.1_7582com_1721.1_7581col_1721.1_131022
Erich P. Ippen and Franco N.C. Wong.
Kuklewicz, Christopher Edward, 1973-
Massachusetts Institute of Technology. Dept. of Physics.
Massachusetts Institute of Technology. Department of Physics
2007-09-27T20:14:09Z
2007-09-27T20:14:09Z
2005
2006
http://hdl.handle.net/1721.1/34647
70145015
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, February 2006.
Includes bibliographical references (leaves 137-141).
This thesis describes the design, construction, and testing of a new source of entanglement. The goal is to produce pairs of photons which are not only polarization-entangled, but also have a high brightness within a narrow bandwidth. This novel source is more suitable than previous SPDC sources for transferring entanglement to future qubit storage such as a trapped rubidium memory. The narrow bandwidth is imposed by modifying the spectrum of the photon pairs by performing the down-conversion inside a cavity. The collinear downconversion geometry inside the linear cavity is achieved by using a quasi-phased-matched periodically-poled potassium titanyl phosphate (PPKTP) crystal. The single-pass free-space photon-pairs produced were demonstrated to be polarization-entangled by measuring the Hong-Ou-Mandel interference dip and measuring a violation of Bell's inequality of 2.711 ± 0.010 (which was greater than the classical limit of 2). The cavity-enhanced downconversion was observed with a brightness of 0.7 pairs/s per mW of pump per MHz of bandwidth in the Gaussian mode collected (a generation rate of 110 pairs/s/mW/MHz is inferred). The interference dip from the pairs was measured to have a visibility of 75% when near the ideal equal-FSR operating point, where the pairs are in the biphoton triplet state. When detuned to have unequal FSR the output pairs show the an interference dip behavior consisting of a combination of triplet and singlet states that depends on the time separation of the pair as it leaves the cavity. The observed results corroborate detailed predictions of a Gaussian-state model of cavity-enhanced downconversion.
by Christopher Edward Kuklewicz.
Ph.D.
141 leaves
eng
Massachusetts Institute of Technology
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.
http://dspace.mit.edu/handle/1721.1/7582
Physics.
Ultrabright source of polarization-entangled photons from cavity-enhanced downconversion
Thesis
application/pdf
Publication
unknown
unknown
<Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="571ffa18-1ff2-4cdf-93af-6534edce0343">
<Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type>
<Language>eng</Language>
<Title>Ultrabright source of polarization-entangled photons from cavity-enhanced downconversion</Title>
<PublishedIn>
<Publication>
</Publication>
</PublishedIn>
<PublicationDate>2006</PublicationDate>
<Authors>
<Author>
<DisplayName>Kuklewicz, Christopher Edward, 1973-</DisplayName>
<Affiliation>
<OrgUnit>
</OrgUnit>
</Affiliation>
</Author>
</Authors>
<Editors>
</Editors>
<Publishers>
<Publisher>
<DisplayName>Massachusetts Institute of Technology</DisplayName>
<OrgUnit />
</Publisher>
</Publishers>
<License>http://dspace.mit.edu/handle/1721.1/7582</License>
<Keyword>Physics.</Keyword>
<Abstract>This thesis describes the design, construction, and testing of a new source of entanglement. The goal is to produce pairs of photons which are not only polarization-entangled, but also have a high brightness within a narrow bandwidth. This novel source is more suitable than previous SPDC sources for transferring entanglement to future qubit storage such as a trapped rubidium memory. The narrow bandwidth is imposed by modifying the spectrum of the photon pairs by performing the down-conversion inside a cavity. The collinear downconversion geometry inside the linear cavity is achieved by using a quasi-phased-matched periodically-poled potassium titanyl phosphate (PPKTP) crystal. The single-pass free-space photon-pairs produced were demonstrated to be polarization-entangled by measuring the Hong-Ou-Mandel interference dip and measuring a violation of Bell's inequality of 2.711 ± 0.010 (which was greater than the classical limit of 2). The cavity-enhanced downconversion was observed with a brightness of 0.7 pairs/s per mW of pump per MHz of bandwidth in the Gaussian mode collected (a generation rate of 110 pairs/s/mW/MHz is inferred). The interference dip from the pairs was measured to have a visibility of 75% when near the ideal equal-FSR operating point, where the pairs are in the biphoton triplet state. When detuned to have unequal FSR the output pairs show the an interference dip behavior consisting of a combination of triplet and singlet states that depends on the time separation of the pair as it leaves the cavity. The observed results corroborate detailed predictions of a Gaussian-state model of cavity-enhanced downconversion.</Abstract>
<Access xmlns="http://purl.org/coar/access_right"
>
</Access>
</Publication>