{"id":{"repo_id":"lsu-thes","oai_identifier":"oai:repository.lsu.edu:gradschool_dissertations-2340"},"canonical_url":"https://search.dev.ndltd.org/etd/lsu-thes/oai:repository.lsu.edu:gradschool_dissertations-2340","repository":{"repo_id":"lsu-thes","name":"Lousiana State University","base_url":"https://repository.lsu.edu/do/oai/"},"display":{"title":"Plasmonic devices for manipulating light at the nanoscale: slow-light waveguides and compact couplers","abstract":"In this dissertation, I explore new plasmonic structures and devices for manipulating light at the nanoscale: slow-light waveguides and compact couplers. I first introduce a plasmonic waveguide system, based on a plasmonic analogue of electromagnetically induced transparency (EIT), which supports a subwavelength slow-light mode, and exhibits a small group velocity dispersion. The system consists of a periodic array of two metal-dielectric-metal (MDM) stub resonators side-coupled to a MDM waveguide. Decreasing the frequency spacing between the two resonances increases the slowdown factor and decreases the bandwidth of the slow-light band. I also show that there is a trade-off between the slowdown factor and the propagation length of the slow-light mode. I next consider Mach-Zehnder interferometer (MZI) sensors in which the sensing arm consists of a slow-light waveguide based on a plasmonic analogue of EIT. I show that a MZI sensor using such a waveguide leads to approximately an order of magnitude enhancement in the refractive index sensitivity, and therefore in the minimum detectable refractive index change, compared to a MZI sensor using a conventional MDM waveguide. I also introduce compact wavelength-scale slit-based structures for coupling free space light into MDM subwavelength plasmonic waveguides. I first show that for a single slit structure the coupling efficiency is limited by a trade-off between the light power coupled into the slit, and the transmission of the slit-MDM waveguide junction. I next consider a two-section slit structure, and show that for such a structure the upper slit section enhances the coupling of the incident light into the lower slit section. The optimized two-section slit structure results in ¡­ 2.3 times enhancement of the coupling into the MDM plasmonic waveguide compared to the optimized single-slit structure. I finally consider a symmetric double-slit structure, and show that for such a structure the surface plasmons excited at the metal-air interfaces are partially coupled into the slits. Thus, the coupling of the incident light into the slits is greatly enhanced, and the optimized double-slit structure results in ¡­ 3.3 times coupling enhancement compared to the optimized single-slit structure. In all cases the coupler response is broadband.","abstract_html":"In this dissertation, I explore new plasmonic structures and devices for manipulating light at the nanoscale: slow-light waveguides and compact couplers. I first introduce a plasmonic waveguide system, based on a plasmonic analogue of electromagnetically induced transparency (EIT), which supports a subwavelength slow-light mode, and exhibits a small group velocity dispersion. The system consists of a periodic array of two metal-dielectric-metal (MDM) stub resonators side-coupled to a MDM waveguide. Decreasing the frequency spacing between the two resonances increases the slowdown factor and decreases the bandwidth of the slow-light band. I also show that there is a trade-off between the slowdown factor and the propagation length of the slow-light mode. I next consider Mach-Zehnder interferometer (MZI) sensors in which the sensing arm consists of a slow-light waveguide based on a plasmonic analogue of EIT. I show that a MZI sensor using such a waveguide leads to approximately an order of magnitude enhancement in the refractive index sensitivity, and therefore in the minimum detectable refractive index change, compared to a MZI sensor using a conventional MDM waveguide. I also introduce compact wavelength-scale slit-based structures for coupling free space light into MDM subwavelength plasmonic waveguides. I first show that for a single slit structure the coupling efficiency is limited by a trade-off between the light power coupled into the slit, and the transmission of the slit-MDM waveguide junction. I next consider a two-section slit structure, and show that for such a structure the upper slit section enhances the coupling of the incident light into the lower slit section. The optimized two-section slit structure results in ¡­ 2.3 times enhancement of the coupling into the MDM plasmonic waveguide compared to the optimized single-slit structure. I finally consider a symmetric double-slit structure, and show that for such a structure the surface plasmons excited at the metal-air interfaces are partially coupled into the slits. Thus, the coupling of the incident light into the slits is greatly enhanced, and the optimized double-slit structure results in ¡­ 3.3 times coupling enhancement compared to the optimized single-slit structure. In all cases the coupler response is broadband.","abstract_has_math":false,"creators":["Huang, Yin"],"institution":"Electrical and Computer Engineering","degree_name":"Doctor of Philosophy (PhD)","degree_level":"Dissertation","degree_discipline":"Electrical and Computer Engineering","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012-01-01T08:00:00Z","date_published":"2012-01-01T08:00:00Z","updated_at":"2026-07-24T02:59:22Z","subjects":["compact couplers","slow light waveguides","plasmonics"],"languages":[],"rights":["unrestricted","Release the entire work immediately for access worldwide."],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["etd-11122012-124413","https://repository.lsu.edu/gradschool_dissertations/1341"],"render_values":[{"text":"etd-11122012-124413","href":null,"code":true},{"text":"https://repository.lsu.edu/gradschool_dissertations/1341","href":"https://repository.lsu.edu/gradschool_dissertations/1341","code":true}]}]},"links":{"outbound_url":"https://doi.org/10.31390/gradschool_dissertations.1341","outbound_label":"DOI","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Huang, Yin"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2012-10-30"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2022-05-12T23:11:48Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical and Computer Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy (PhD)"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Electrical and Computer Engineering"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["compact couplers","slow light waveguides","plasmonics"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["unrestricted","Release the entire work immediately for access worldwide."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["etd-11122012-124413","10.31390/gradschool_dissertations.1341","https://repository.lsu.edu/gradschool_dissertations/1341"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["In this dissertation, I explore new plasmonic structures and devices for manipulating light at the nanoscale: slow-light waveguides and compact couplers. I first introduce a plasmonic waveguide system, based on a plasmonic analogue of electromagnetically induced transparency (EIT), which supports a subwavelength slow-light mode, and exhibits a small group velocity dispersion. The system consists of a periodic array of two metal-dielectric-metal (MDM) stub resonators side-coupled to a MDM waveguide. Decreasing the frequency spacing between the two resonances increases the slowdown factor and decreases the bandwidth of the slow-light band. I also show that there is a trade-off between the slowdown factor and the propagation length of the slow-light mode. I next consider Mach-Zehnder interferometer (MZI) sensors in which the sensing arm consists of a slow-light waveguide based on a plasmonic analogue of EIT. I show that a MZI sensor using such a waveguide leads to approximately an order of magnitude enhancement in the refractive index sensitivity, and therefore in the minimum detectable refractive index change, compared to a MZI sensor using a conventional MDM waveguide. I also introduce compact wavelength-scale slit-based structures for coupling free space light into MDM subwavelength plasmonic waveguides. I first show that for a single slit structure the coupling efficiency is limited by a trade-off between the light power coupled into the slit, and the transmission of the slit-MDM waveguide junction. I next consider a two-section slit structure, and show that for such a structure the upper slit section enhances the coupling of the incident light into the lower slit section. The optimized two-section slit structure results in ¡­ 2.3 times enhancement of the coupling into the MDM plasmonic waveguide compared to the optimized single-slit structure. I finally consider a symmetric double-slit structure, and show that for such a structure the surface plasmons excited at the metal-air interfaces are partially coupled into the slits. Thus, the coupling of the incident light into the slits is greatly enhanced, and the optimized double-slit structure results in ¡­ 3.3 times coupling enhancement compared to the optimized single-slit structure. In all cases the coupler response is broadband."]},{"key":"dc:title","label":"Title","values":["Plasmonic devices for manipulating light at the nanoscale: slow-light waveguides and compact couplers"]}]}],"canonical_facts":{"dc:creator":["Huang, Yin"],"dc:date":["2012-10-30"],"dc:date.available":["2022-05-12T23:11:48Z"],"dc:description.abstract":["In this dissertation, I explore new plasmonic structures and devices for manipulating light at the nanoscale: slow-light waveguides and compact couplers. I first introduce a plasmonic waveguide system, based on a plasmonic analogue of electromagnetically induced transparency (EIT), which supports a subwavelength slow-light mode, and exhibits a small group velocity dispersion. The system consists of a periodic array of two metal-dielectric-metal (MDM) stub resonators side-coupled to a MDM waveguide. Decreasing the frequency spacing between the two resonances increases the slowdown factor and decreases the bandwidth of the slow-light band. I also show that there is a trade-off between the slowdown factor and the propagation length of the slow-light mode. I next consider Mach-Zehnder interferometer (MZI) sensors in which the sensing arm consists of a slow-light waveguide based on a plasmonic analogue of EIT. I show that a MZI sensor using such a waveguide leads to approximately an order of magnitude enhancement in the refractive index sensitivity, and therefore in the minimum detectable refractive index change, compared to a MZI sensor using a conventional MDM waveguide. I also introduce compact wavelength-scale slit-based structures for coupling free space light into MDM subwavelength plasmonic waveguides. I first show that for a single slit structure the coupling efficiency is limited by a trade-off between the light power coupled into the slit, and the transmission of the slit-MDM waveguide junction. I next consider a two-section slit structure, and show that for such a structure the upper slit section enhances the coupling of the incident light into the lower slit section. The optimized two-section slit structure results in ¡­ 2.3 times enhancement of the coupling into the MDM plasmonic waveguide compared to the optimized single-slit structure. I finally consider a symmetric double-slit structure, and show that for such a structure the surface plasmons excited at the metal-air interfaces are partially coupled into the slits. Thus, the coupling of the incident light into the slits is greatly enhanced, and the optimized double-slit structure results in ¡­ 3.3 times coupling enhancement compared to the optimized single-slit structure. In all cases the coupler response is broadband."],"dc:identifier":["etd-11122012-124413","10.31390/gradschool_dissertations.1341","https://repository.lsu.edu/gradschool_dissertations/1341"],"dc:rights":["unrestricted","Release the entire work immediately for access worldwide."],"dc:subject":["compact couplers","slow light waveguides","plasmonics"],"dc:title":["Plasmonic devices for manipulating light at the nanoscale: slow-light waveguides and compact couplers"],"thesis:degree_discipline":["Electrical and Computer Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy (PhD)"],"thesis:institution_name":["Electrical and Computer Engineering"]},"updated_at":"2026-07-24T02:59:22Z"}