{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/23899"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/23899","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Time-resolved Raman scattering in GaAs multiple quantum well structures","abstract":"This thesis describes an optical study of the intersubband relaxation of carriers in GaAs multiple quantum well structures. For this investigation the application of the conventional Raman scattering technique was extended to the picosecond time domain. Inelastic light scattering from the elementary intersubband excitations of an electron-hole plasma reveals both the absolute carrier density and the occupancy of the electronic subbands of a GaAs quantum welL The major result of this investigation concerns the role of the intersubband scattering processes in the relaxation of carriers following their excitation in a GaAs quantum well by a short optical pulse. Carriers generated on the second subband of a wide quantum well relax towards the bottom of the well by the emission of acoustic phonon. Their lifetime is found equal to 325±25 picoseconds in a 215 A multiple quantum well structure, whereas in a narrower well (116 A) the lifetime is reduced behond our experimental time resolution of 8 ps, presumably caused by the faster relaxation mechanism corresponding to the emission of an optical phonon. A theoretical calculation of the scattering rate by longitudinal acoustic phonon supports the existence of a long-lived electron population on the second subband of a wide GaAs quantum well.","abstract_html":"This thesis describes an optical study of the intersubband relaxation of carriers in GaAs multiple quantum well structures. For this investigation the application of the conventional Raman scattering technique was extended to the picosecond time domain. Inelastic light scattering from the elementary intersubband excitations of an electron-hole plasma reveals both the absolute carrier density and the occupancy of the electronic subbands of a GaAs quantum welL The major result of this investigation concerns the role of the intersubband scattering processes in the relaxation of carriers following their excitation in a GaAs quantum well by a short optical pulse. Carriers generated on the second subband of a wide quantum well relax towards the bottom of the well by the emission of acoustic phonon. Their lifetime is found equal to 325±25 picoseconds in a 215 A multiple quantum well structure, whereas in a narrower well (116 A) the lifetime is reduced behond our experimental time resolution of 8 ps, presumably caused by the faster relaxation mechanism corresponding to the emission of an optical phonon. A theoretical calculation of the scattering rate by longitudinal acoustic phonon supports the existence of a long-lived electron population on the second subband of a wide GaAs quantum well.","abstract_has_math":false,"creators":["Oberli, Daniel Yves"],"institution":null,"degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Klein, Miles V."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-16T21:02:49Z","date_published":"2011-05-16T21:02:49Z","updated_at":"2026-07-22T22:25:22Z","subjects":["time-resolved Raman scattering","GaAs","multiple quantum well structures","intersubband relaxation"],"languages":["en"],"rights":["1988 Daniel Yves Oberli"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["3471802"],"render_values":[{"text":"3471802","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/23899","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Klein, Miles V."]},{"key":"dc:creator","label":"Author","values":["Oberli, Daniel Yves"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-16T21:02:49Z","10000-01-01","1988"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation / Thesis","text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Physics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["time-resolved Raman scattering","GaAs","multiple quantum well structures","intersubband relaxation"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["1988 Daniel Yves Oberli"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["3471802","http://hdl.handle.net/2142/23899"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["This thesis describes an optical study of the intersubband relaxation of carriers in GaAs multiple quantum well structures. For this investigation the application of the conventional Raman scattering technique was extended to the picosecond time domain. Inelastic light scattering from the elementary intersubband excitations of an electron-hole plasma reveals both the absolute carrier density and the occupancy of the electronic subbands of a GaAs quantum welL The major result of this investigation concerns the role of the intersubband scattering processes in the relaxation of carriers following their excitation in a GaAs quantum well by a short optical pulse. Carriers generated on the second subband of a wide quantum well relax towards the bottom of the well by the emission of acoustic phonon. Their lifetime is found equal to 325±25 picoseconds in a 215 A multiple quantum well structure, whereas in a narrower well (116 A) the lifetime is reduced behond our experimental time resolution of 8 ps, presumably caused by the faster relaxation mechanism corresponding to the emission of an optical phonon. A theoretical calculation of the scattering rate by longitudinal acoustic phonon supports the existence of a long-lived electron population on the second subband of a wide GaAs quantum well.","Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-05-16T21:02:49Z No. of bitstreams: 1 1988_oberli.pdf: 5996775 bytes, checksum: b8ac9a004aa51297c9513898bf69f5a3 (MD5)","Made available in DSpace on 2011-05-16T21:02:49Z (GMT). No. of bitstreams: 1 1988_oberli.pdf: 5996775 bytes, checksum: b8ac9a004aa51297c9513898bf69f5a3 (MD5) Previous issue date: 1988","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-05-16T21:02:49Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:13:58-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis","Thesis","U of I Only"]},{"key":"dc:title","label":"Title","values":["Time-resolved Raman scattering in GaAs multiple quantum well structures"]}]}],"canonical_facts":{"dc:contributor":["Klein, Miles V."],"dc:creator":["Oberli, Daniel Yves"],"dc:date":["2011-05-16T21:02:49Z","10000-01-01","1988"],"dc:description":["This thesis describes an optical study of the intersubband relaxation of carriers in GaAs multiple quantum well structures. For this investigation the application of the conventional Raman scattering technique was extended to the picosecond time domain. Inelastic light scattering from the elementary intersubband excitations of an electron-hole plasma reveals both the absolute carrier density and the occupancy of the electronic subbands of a GaAs quantum welL The major result of this investigation concerns the role of the intersubband scattering processes in the relaxation of carriers following their excitation in a GaAs quantum well by a short optical pulse. Carriers generated on the second subband of a wide quantum well relax towards the bottom of the well by the emission of acoustic phonon. Their lifetime is found equal to 325±25 picoseconds in a 215 A multiple quantum well structure, whereas in a narrower well (116 A) the lifetime is reduced behond our experimental time resolution of 8 ps, presumably caused by the faster relaxation mechanism corresponding to the emission of an optical phonon. A theoretical calculation of the scattering rate by longitudinal acoustic phonon supports the existence of a long-lived electron population on the second subband of a wide GaAs quantum well.","Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-05-16T21:02:49Z No. of bitstreams: 1 1988_oberli.pdf: 5996775 bytes, checksum: b8ac9a004aa51297c9513898bf69f5a3 (MD5)","Made available in DSpace on 2011-05-16T21:02:49Z (GMT). No. of bitstreams: 1 1988_oberli.pdf: 5996775 bytes, checksum: b8ac9a004aa51297c9513898bf69f5a3 (MD5) Previous issue date: 1988","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-05-16T21:02:49Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:13:58-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis","Thesis","U of I Only"],"dc:identifier":["3471802","http://hdl.handle.net/2142/23899"],"dc:language":["en"],"dc:rights":["1988 Daniel Yves Oberli"],"dc:subject":["time-resolved Raman scattering","GaAs","multiple quantum well structures","intersubband relaxation"],"dc:title":["Time-resolved Raman scattering in GaAs multiple quantum well structures"],"dc:type":["Dissertation / Thesis","text"],"thesis:degree_discipline":["Physics"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."]},"updated_at":"2026-07-22T22:25:22Z"}