{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/14767"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/14767","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Graded wavelength filter based wavelength detection for a distributed feedback laser biosensor","abstract":"Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2009-12-11T18:39:31Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 2 Altaf_Kashif.docx: 2180725 bytes, checksum: 1eda169a0e92f4bceba9ba7fb757bf1c (MD5) Altaf_Kashif.pdf: 13322684 bytes, checksum: c3ed1bf573cb5bed6e60b8163bdf34cb (MD5)","abstract_html":"Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2009-12-11T18:39:31Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 2 Altaf_Kashif.docx: 2180725 bytes, checksum: 1eda169a0e92f4bceba9ba7fb757bf1c (MD5) Altaf_Kashif.pdf: 13322684 bytes, checksum: c3ed1bf573cb5bed6e60b8163bdf34cb (MD5)","abstract_has_math":false,"creators":["Altaf, Kashif"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Electrical & Computer Engr","degree_department":null,"school":null,"contributors":["Cunningham, Brian T."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2010,"date_issued":"2010-01-06T17:50:15Z","date_published":"2010-01-06T17:50:15Z","updated_at":"2026-07-22T22:25:08Z","subjects":["Graded wavelength filter","wavelength detection."],"languages":["en"],"rights":["Copyright 2009 Kashif Altaf"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/14767","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Cunningham, Brian T."]},{"key":"dc:creator","label":"Author","values":["Altaf, Kashif"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2010-01-06T17:50:15Z","2012-01-07T11:00:12Z","2009-12"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical & Computer Engr"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Graded wavelength filter","wavelength detection."]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2009 Kashif Altaf"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/14767"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2009-12-11T18:39:31Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 2 Altaf_Kashif.docx: 2180725 bytes, checksum: 1eda169a0e92f4bceba9ba7fb757bf1c (MD5) Altaf_Kashif.pdf: 13322684 bytes, checksum: c3ed1bf573cb5bed6e60b8163bdf34cb (MD5)","Made available in DSpace on 2010-01-06T17:50:15Z (GMT). No. of bitstreams: 3 Altaf_Kashif.docx: 2180725 bytes, checksum: 1eda169a0e92f4bceba9ba7fb757bf1c (MD5) license.txt: 4061 bytes, checksum: 7159109dc5af783a605b79c40924b4ef (MD5) Altaf_Kashif.pdf: 13322684 bytes, checksum: c3ed1bf573cb5bed6e60b8163bdf34cb (MD5)","Item marked as restricted to the 'Administrator' Group (id=1) by William Ingram (wingram2@illinois.edu) on 2010-01-06T17:50:32Z Item is restricted until 2012-01-06T17:50:31Z","A compact and low-cost wavelength detection system has been designed that works for the readout of the distributed feedback (DFB) laser biosensor. The detection system is based on a charge-coupled device (CCD) array, and on a guided mode resonance filter (GMRF) that is composed of a linear dielectric grating and a linearly graded high-refractive-index titanium dioxide (TiO2) thin film, whose thickness varies as a function of position on the surface. The size of the setup is almost the same as the size of the CCD chip. The GMRF exhibits linearly varying wavelength reflectance characteristics, i.e., resonant wavelength values that are a function of the thickness of the TiO2 film. The filter is designed to perform real-time biosensing of a DFB laser biosensor that is also composed of a linear dielectric grating, an active dye-doped polymer layer and a uniform-thickness TiO2 thin film deposited on its surface. When excited with a high energy pulsed Nd:YAG laser, the DFB laser emits narrowband stimulated emission whose wavelength changes as a function of the effective refractive index of the DFB structure being excited. Alternating oppositely charged polyelectrolyte monolayers have been deposited on the DFB surface that generate wavelength shifts in small steps due to increasing thickness of the polyelectrolyte stack, thereby changing the effective refractive index with each adsorbed monolayer. The gratings for both the graded wavelength filter (GWF) and the DFB laser structures are fabricated by a low-cost and high-throughput process of nanoreplica molding. The wavelength sensing mechanism is found to be robust and measures wavelength shifts with a spectral resolution of 308 pm.","Item reinstated by Sarah Shreeves (sshreeve@illinois.edu) on 2012-01-07T11:00:12Z Item was in collections: Dissertations and Theses - Electrical and Computer Engineering (ID: 446) University of Illinois Dissertations and Theses (ID: 204) No. of bitstreams: 4 Altaf_Kashif.pdf.txt: 73989 bytes, checksum: 770bbde4f06fc0c1943b0b1761c7d778 (MD5) Altaf_Kashif.docx: 2180725 bytes, checksum: 1eda169a0e92f4bceba9ba7fb757bf1c (MD5) license.txt: 4061 bytes, checksum: 7159109dc5af783a605b79c40924b4ef (MD5) Altaf_Kashif.pdf: 13322684 bytes, checksum: c3ed1bf573cb5bed6e60b8163bdf34cb (MD5)","Item released from any restrictions by Sarah Shreeves (sshreeve@illinois.edu) on 2012-01-07T11:00:12Z"]},{"key":"dc:title","label":"Title","values":["Graded wavelength filter based wavelength detection for a distributed feedback laser biosensor"]}]}],"canonical_facts":{"dc:contributor":["Cunningham, Brian T."],"dc:creator":["Altaf, Kashif"],"dc:date":["2010-01-06T17:50:15Z","2012-01-07T11:00:12Z","2009-12"],"dc:description":["Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2009-12-11T18:39:31Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 2 Altaf_Kashif.docx: 2180725 bytes, checksum: 1eda169a0e92f4bceba9ba7fb757bf1c (MD5) Altaf_Kashif.pdf: 13322684 bytes, checksum: c3ed1bf573cb5bed6e60b8163bdf34cb (MD5)","Made available in DSpace on 2010-01-06T17:50:15Z (GMT). No. of bitstreams: 3 Altaf_Kashif.docx: 2180725 bytes, checksum: 1eda169a0e92f4bceba9ba7fb757bf1c (MD5) license.txt: 4061 bytes, checksum: 7159109dc5af783a605b79c40924b4ef (MD5) Altaf_Kashif.pdf: 13322684 bytes, checksum: c3ed1bf573cb5bed6e60b8163bdf34cb (MD5)","Item marked as restricted to the 'Administrator' Group (id=1) by William Ingram (wingram2@illinois.edu) on 2010-01-06T17:50:32Z Item is restricted until 2012-01-06T17:50:31Z","A compact and low-cost wavelength detection system has been designed that works for the readout of the distributed feedback (DFB) laser biosensor. The detection system is based on a charge-coupled device (CCD) array, and on a guided mode resonance filter (GMRF) that is composed of a linear dielectric grating and a linearly graded high-refractive-index titanium dioxide (TiO2) thin film, whose thickness varies as a function of position on the surface. The size of the setup is almost the same as the size of the CCD chip. The GMRF exhibits linearly varying wavelength reflectance characteristics, i.e., resonant wavelength values that are a function of the thickness of the TiO2 film. The filter is designed to perform real-time biosensing of a DFB laser biosensor that is also composed of a linear dielectric grating, an active dye-doped polymer layer and a uniform-thickness TiO2 thin film deposited on its surface. When excited with a high energy pulsed Nd:YAG laser, the DFB laser emits narrowband stimulated emission whose wavelength changes as a function of the effective refractive index of the DFB structure being excited. Alternating oppositely charged polyelectrolyte monolayers have been deposited on the DFB surface that generate wavelength shifts in small steps due to increasing thickness of the polyelectrolyte stack, thereby changing the effective refractive index with each adsorbed monolayer. The gratings for both the graded wavelength filter (GWF) and the DFB laser structures are fabricated by a low-cost and high-throughput process of nanoreplica molding. The wavelength sensing mechanism is found to be robust and measures wavelength shifts with a spectral resolution of 308 pm.","Item reinstated by Sarah Shreeves (sshreeve@illinois.edu) on 2012-01-07T11:00:12Z Item was in collections: Dissertations and Theses - Electrical and Computer Engineering (ID: 446) University of Illinois Dissertations and Theses (ID: 204) No. of bitstreams: 4 Altaf_Kashif.pdf.txt: 73989 bytes, checksum: 770bbde4f06fc0c1943b0b1761c7d778 (MD5) Altaf_Kashif.docx: 2180725 bytes, checksum: 1eda169a0e92f4bceba9ba7fb757bf1c (MD5) license.txt: 4061 bytes, checksum: 7159109dc5af783a605b79c40924b4ef (MD5) Altaf_Kashif.pdf: 13322684 bytes, checksum: c3ed1bf573cb5bed6e60b8163bdf34cb (MD5)","Item released from any restrictions by Sarah Shreeves (sshreeve@illinois.edu) on 2012-01-07T11:00:12Z"],"dc:identifier":["http://hdl.handle.net/2142/14767"],"dc:language":["en"],"dc:rights":["Copyright 2009 Kashif Altaf"],"dc:subject":["Graded wavelength filter","wavelength detection."],"dc:title":["Graded wavelength filter based wavelength detection for a distributed feedback laser biosensor"],"thesis:degree_discipline":["Electrical & Computer Engr"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:08Z"}