{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/129750"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/129750","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Enhanced beam quality and polarization stability in oxide-confined Vertical-Cavity Surface-Emitting Lasers via anti-phase optical coatings and disorder-defined apertures","abstract":"Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2027-05-01","abstract_html":"Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2027-05-01","abstract_has_math":false,"creators":["Pikul, Kevin Peter"],"institution":"University of Illinois Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Electrical & Computer Engr","degree_department":null,"school":null,"contributors":["Dallesasse, John M","Feng, Milton","Lee, Minjoo","Dragic, Peter D"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-04-30","date_published":"2025-04-30","updated_at":"2026-07-22T22:25:05Z","subjects":["VCSEL","single-transverse mode","single-polarization state","anti-phase optical coating","silicon optical coating","impurity-induced disordering","disorder-defined aperture"],"languages":["en","eng"],"rights":["Copyright 2025 Kevin Pikul"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/2142/129750","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Dallesasse, John M","Feng, Milton","Lee, Minjoo","Dragic, Peter D"]},{"key":"dc:creator","label":"Author","values":["Pikul, Kevin Peter"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2025-04-30","2025-05"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical & Computer Engr"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["VCSEL","single-transverse mode","single-polarization state","anti-phase optical coating","silicon optical coating","impurity-induced disordering","disorder-defined aperture"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en","eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2025 Kevin Pikul"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2142/129750"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2027-05-01","The student, Kevin Pikul, accepted the attached license on 2025-04-29 at 12:29.","The student, Kevin Pikul, submitted this Dissertation for approval on 2025-04-30 at 11:41.","This Dissertation was approved for publication on 2025-04-30 at 12:58.","DSpace SAF Submission Ingestion Package generated from Vireo submission #22084 on 2025-10-19 at 19:54:37","The Vertical-Cavity Surface-Emitting Laser (VCSEL) has become ubiquitous in the modern world, with applications spanning the optical telecommunications infrastructure in the form of short-haul optical transceivers, optical printers, and optical “mice.” This is a result of its energy-efficient operation, small footprint, and capability for packaging into 2-dimensional arrays. Emerging technologies in 3D-sensing for consumer handheld products, augmented reality/virtual reality (AR/VR) headsets, and light detection and ranging (LiDAR) have begun to reach operational limits of current VCSELs. The development of VCSELs capable of operating in a single-transverse mode with a stable single polarization and high output optical powers is paramount. Operation in this regime is advantageous for many reasons, including less divergence in the optical beam leading to a smaller spot size, higher optical signal-to-noise ratio (SNR), and spectral purity and stability. The anti-phase coating introduced in this work accomplishes these operational objectives via the deposition of a single layer of silicon atop the VCSEL patterned with a circular or elliptical aperture. This creates a radially-varying threshold modal gain, sufficient for suppressing higher-order transverse modes or unpreferred polarization states without disrupting the cylindrically-symmetric transverse optical modes defined by the circular oxide aperture, maintaining the symmetrical integrity of the modes. Another mode- and polarization-control technique discussed in this dissertation is impurity-induced layer disordering for the formation of disorder-defined apertures. By diffusing zinc into the periphery of a VCSEL top DBR, the number of DBR pairs is reduced, raising the threshold modal gain for the modes overlapping with the zinc difused region, mainly the higher-order transverse modes. The following dissertation primarily investigates the anti-phase coating as a mode- and polarization-control method in 850 nm GaAs-based oxide-cofined VCSELs, both discrete devices and arrays. The VCSEL structure is simulated to develop an optimal anti-phase coating structure, and the devices are then fabricated following a standard oxide-confined VCSEL process flow. The VCSELs are then characterized for output power and spectral performance via light-current-voltage (LIV) curves and optical spectra measurements. To realize single-polarization operation, polarization-resolved LIV (PR-LIV) measurements are taken. This dissertation also investigates the use of disorder-defined apertures for single-mode, single-polarization operation in 2D-arrays and how the combination of both techniques can result in single-mode performance in multimode VCSELs utilizing only one technique. To conclude, an overview of long-wavelength VCSELs will occur, followed by the simulation of several epitaxial materials and design of a novel long wavelength VCSEL structure."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Enhanced beam quality and polarization stability in oxide-confined Vertical-Cavity Surface-Emitting Lasers via anti-phase optical coatings and disorder-defined apertures"]}]}],"canonical_facts":{"dc:contributor":["Dallesasse, John M","Feng, Milton","Lee, Minjoo","Dragic, Peter D"],"dc:creator":["Pikul, Kevin Peter"],"dc:date":["2025-04-30","2025-05"],"dc:description":["Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2027-05-01","The student, Kevin Pikul, accepted the attached license on 2025-04-29 at 12:29.","The student, Kevin Pikul, submitted this Dissertation for approval on 2025-04-30 at 11:41.","This Dissertation was approved for publication on 2025-04-30 at 12:58.","DSpace SAF Submission Ingestion Package generated from Vireo submission #22084 on 2025-10-19 at 19:54:37","The Vertical-Cavity Surface-Emitting Laser (VCSEL) has become ubiquitous in the modern world, with applications spanning the optical telecommunications infrastructure in the form of short-haul optical transceivers, optical printers, and optical “mice.” This is a result of its energy-efficient operation, small footprint, and capability for packaging into 2-dimensional arrays. Emerging technologies in 3D-sensing for consumer handheld products, augmented reality/virtual reality (AR/VR) headsets, and light detection and ranging (LiDAR) have begun to reach operational limits of current VCSELs. The development of VCSELs capable of operating in a single-transverse mode with a stable single polarization and high output optical powers is paramount. Operation in this regime is advantageous for many reasons, including less divergence in the optical beam leading to a smaller spot size, higher optical signal-to-noise ratio (SNR), and spectral purity and stability. The anti-phase coating introduced in this work accomplishes these operational objectives via the deposition of a single layer of silicon atop the VCSEL patterned with a circular or elliptical aperture. This creates a radially-varying threshold modal gain, sufficient for suppressing higher-order transverse modes or unpreferred polarization states without disrupting the cylindrically-symmetric transverse optical modes defined by the circular oxide aperture, maintaining the symmetrical integrity of the modes. Another mode- and polarization-control technique discussed in this dissertation is impurity-induced layer disordering for the formation of disorder-defined apertures. By diffusing zinc into the periphery of a VCSEL top DBR, the number of DBR pairs is reduced, raising the threshold modal gain for the modes overlapping with the zinc difused region, mainly the higher-order transverse modes. The following dissertation primarily investigates the anti-phase coating as a mode- and polarization-control method in 850 nm GaAs-based oxide-cofined VCSELs, both discrete devices and arrays. The VCSEL structure is simulated to develop an optimal anti-phase coating structure, and the devices are then fabricated following a standard oxide-confined VCSEL process flow. The VCSELs are then characterized for output power and spectral performance via light-current-voltage (LIV) curves and optical spectra measurements. To realize single-polarization operation, polarization-resolved LIV (PR-LIV) measurements are taken. This dissertation also investigates the use of disorder-defined apertures for single-mode, single-polarization operation in 2D-arrays and how the combination of both techniques can result in single-mode performance in multimode VCSELs utilizing only one technique. To conclude, an overview of long-wavelength VCSELs will occur, followed by the simulation of several epitaxial materials and design of a novel long wavelength VCSEL structure."],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2142/129750"],"dc:language":["en","eng"],"dc:rights":["Copyright 2025 Kevin Pikul"],"dc:subject":["VCSEL","single-transverse mode","single-polarization state","anti-phase optical coating","silicon optical coating","impurity-induced disordering","disorder-defined aperture"],"dc:title":["Enhanced beam quality and polarization stability in oxide-confined Vertical-Cavity Surface-Emitting Lasers via anti-phase optical coatings and disorder-defined apertures"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Electrical & Computer Engr"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:05Z"}