{"id":{"repo_id":"toronto-retro","oai_identifier":"oai:utoronto.scholaris.ca:1807/72963"},"canonical_url":"https://search.dev.ndltd.org/etd/toronto-retro/oai:utoronto.scholaris.ca:1807/72963","repository":{"repo_id":"toronto-retro","name":"University of Toronto","base_url":"https://utoronto.scholaris.ca/server/oai/request"},"display":{"title":"8-Port Homodyne Detection of EIT-enhanced Cross-phase Modulation Using Broadband Signal Pulses","abstract":"This thesis summarizes my work on the interactions between light and matter in the context of optical quantum information processing. I have designed and implemented a phase-sensitive detection scheme for optical-frequency electromagnetic fields, which has been used to measure μrad phase shifts on nanosecond timescales. This phase measurement was developed for the express purpose of detecting cross-phase modulation (XPM), a key ingredient in the construction of optical logic gates. I have implemented the 'N-scheme', a form of XPM which exploits electromagnetically-induced transparency (EIT) and which was promised to yield 'giant' optical nonlinearities sufficient for all-optical quantum information processing. Using a cloud of laser-cooled 85Rb atoms as the nonlinear medium, I present the first ever experimental study of EIT-enhanced XPM in the controversial regime of broadband signal pulses and spectrally narrow EIT windows. The results of this experiment constitute a breakdown of the original proposal for EIT-enhanced XPM. In light of these findings, I conclude with a theoretical analysis of the feasibility of using N-scheme as implemented in our lab to perform a non-demolition measurement of a single photon (a crucial step when using XPM to generate a universal optical logic gate). While possible in principle, the experimental conditions necessary to achieve a signal-to-noise ratio above unity are found to be practically unrealistic, suggesting a more sophisticated scheme is necessary.","abstract_html":"This thesis summarizes my work on the interactions between light and matter in the context of optical quantum information processing. I have designed and implemented a phase-sensitive detection scheme for optical-frequency electromagnetic fields, which has been used to measure μrad phase shifts on nanosecond timescales. This phase measurement was developed for the express purpose of detecting cross-phase modulation (XPM), a key ingredient in the construction of optical logic gates. I have implemented the 'N-scheme', a form of XPM which exploits electromagnetically-induced transparency (EIT) and which was promised to yield 'giant' optical nonlinearities sufficient for all-optical quantum information processing. Using a cloud of laser-cooled 85Rb atoms as the nonlinear medium, I present the first ever experimental study of EIT-enhanced XPM in the controversial regime of broadband signal pulses and spectrally narrow EIT windows. The results of this experiment constitute a breakdown of the original proposal for EIT-enhanced XPM. In light of these findings, I conclude with a theoretical analysis of the feasibility of using N-scheme as implemented in our lab to perform a non-demolition measurement of a single photon (a crucial step when using XPM to generate a universal optical logic gate). While possible in principle, the experimental conditions necessary to achieve a signal-to-noise ratio above unity are found to be practically unrealistic, suggesting a more sophisticated scheme is necessary.","abstract_has_math":false,"creators":["Dmochowski, Greg"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Physics","school":null,"contributors":[],"advisors":["Steinberg, Aephraim M"],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-06","date_published":"2016-06","updated_at":"2026-07-27T21:28:22Z","subjects":[],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1807/72963","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Steinberg, Aephraim M"]},{"key":"dc:contributor.department","label":"Department","values":["Physics"]},{"key":"dc:creator","label":"Author","values":["Dmochowski, Greg"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2016-06"]},{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2016-07-11T23:00:21Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2016-07-11T23:00:21Z"]},{"key":"dc:date.issued","label":"Date","values":["2016-06"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1807/72963"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This thesis summarizes my work on the interactions between light and matter in the context of optical quantum information processing. I have designed and implemented a phase-sensitive detection scheme for optical-frequency electromagnetic fields, which has been used to measure μrad phase shifts on nanosecond timescales. This phase measurement was developed for the express purpose of detecting cross-phase modulation (XPM), a key ingredient in the construction of optical logic gates. I have implemented the 'N-scheme', a form of XPM which exploits electromagnetically-induced transparency (EIT) and which was promised to yield 'giant' optical nonlinearities sufficient for all-optical quantum information processing. Using a cloud of laser-cooled 85Rb atoms as the nonlinear medium, I present the first ever experimental study of EIT-enhanced XPM in the controversial regime of broadband signal pulses and spectrally narrow EIT windows. The results of this experiment constitute a breakdown of the original proposal for EIT-enhanced XPM. In light of these findings, I conclude with a theoretical analysis of the feasibility of using N-scheme as implemented in our lab to perform a non-demolition measurement of a single photon (a crucial step when using XPM to generate a universal optical logic gate). While possible in principle, the experimental conditions necessary to achieve a signal-to-noise ratio above unity are found to be practically unrealistic, suggesting a more sophisticated scheme is necessary."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph.D."]},{"key":"dc:title","label":"Title","values":["8-Port Homodyne Detection of EIT-enhanced Cross-phase Modulation Using Broadband Signal Pulses"]}]}],"canonical_facts":{"dc:contributor.advisor":["Steinberg, Aephraim M"],"dc:contributor.department":["Physics"],"dc:creator":["Dmochowski, Greg"],"dc:date":["2016-06"],"dc:date.accessioned":["2016-07-11T23:00:21Z"],"dc:date.available":["2016-07-11T23:00:21Z"],"dc:date.issued":["2016-06"],"dc:description.abstract":["This thesis summarizes my work on the interactions between light and matter in the context of optical quantum information processing. I have designed and implemented a phase-sensitive detection scheme for optical-frequency electromagnetic fields, which has been used to measure μrad phase shifts on nanosecond timescales. This phase measurement was developed for the express purpose of detecting cross-phase modulation (XPM), a key ingredient in the construction of optical logic gates. I have implemented the 'N-scheme', a form of XPM which exploits electromagnetically-induced transparency (EIT) and which was promised to yield 'giant' optical nonlinearities sufficient for all-optical quantum information processing. Using a cloud of laser-cooled 85Rb atoms as the nonlinear medium, I present the first ever experimental study of EIT-enhanced XPM in the controversial regime of broadband signal pulses and spectrally narrow EIT windows. The results of this experiment constitute a breakdown of the original proposal for EIT-enhanced XPM. In light of these findings, I conclude with a theoretical analysis of the feasibility of using N-scheme as implemented in our lab to perform a non-demolition measurement of a single photon (a crucial step when using XPM to generate a universal optical logic gate). While possible in principle, the experimental conditions necessary to achieve a signal-to-noise ratio above unity are found to be practically unrealistic, suggesting a more sophisticated scheme is necessary."],"dc:description.degree":["Ph.D."],"dc:identifier.uri":["http://hdl.handle.net/1807/72963"],"dc:title":["8-Port Homodyne Detection of EIT-enhanced Cross-phase Modulation Using Broadband Signal Pulses"],"dc:type":["Thesis"]},"updated_at":"2026-07-27T21:28:22Z"}