{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/120327"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/120327","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"High-speed oxide-VCSELS for optical data links in data center and cryogenic computing applications","abstract":"Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2025-05-01","abstract_html":"Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2025-05-01","abstract_has_math":false,"creators":["Fu, Wenning"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Electrical & Computer Engr","degree_department":null,"school":null,"contributors":["Feng, Milton","Jin, Jianming","Dragic, Peter D","Lee, Minjoo Lawrence"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2023,"date_issued":"2023-05","date_published":"2023-05","updated_at":"2026-07-22T22:24:57Z","subjects":["High-speed Communication","Oxide Vcsels"],"languages":["en","eng"],"rights":["Copyright 2023 Wenning Fu"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/2142/120327","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Feng, Milton","Jin, Jianming","Dragic, Peter D","Lee, Minjoo Lawrence"]},{"key":"dc:creator","label":"Author","values":["Fu, Wenning"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2023-05","2023-01-04"]},{"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 at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["High-speed Communication","Oxide Vcsels"]}]},{"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 2023 Wenning Fu"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2142/120327"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2025-05-01","The student, Wenning Fu, accepted the attached license on 2022-12-16 at 11:51.","The student, Wenning Fu, submitted this Dissertation for approval on 2022-12-16 at 12:21.","This Dissertation was approved for publication on 2023-01-04 at 13:36.","DSpace SAF Submission Ingestion Package generated from Vireo submission #18804 on 2023-09-01 at 17:12:16","In recent years, there is a growing demand for a high-speed and power-efficient data extraction from cryogenic environments, such as superconducting processors based on single flux quantum (SFQ) technology at 4 Kelvin (K). To achieve such data transfer from 4 K to room-temperature electronics, optical data links based on cryogenic VCSELs at 4 K or an intermediate temperature are promising solutions due to low signal loss and low heat leak in fibers. The main work demonstrated in this dissertation is the development of a record high-speed cryogenic VCSEL with optical data transmission over 50 Gb/s from liquid-nitrogen and liquid-helium temperature to room-temperature electronics. Furthermore, the bandwidth measurement, microwave modeling, and parameter extraction have indicated that the capability of the cryogenic VCSELs is far beyond 50 Gb/s data rate. The extracted intrinsic bandwidth of 88.7 GHz at liquid-nitrogen temperature projects to a 200 Gb/s, sub-100 fJ/bit single-VCSEL, single-fiber data link. Also reported is the first demonstration that superconducting circuits are used to modulate a fully packaged VCSEL for up to 20 Gb/s NRZ data transmission via a fiber link from 4 K all the way to room-temperature users. The data rate is limited by the superconducting processor available to use. The authors believe that this work paves the way for next-generation cryogenic computing technologies by solving one of the key issues: the need of a high-speed, efficient, and low-heat-leak data communication between cryogenic and room-temperature environments. To make a transition into the cryogenic VCSEL development chapter, room-temperature VCSEL development, which was partially contributed by the author, is presented first. For many years, room-temperature GaAs-based 850nm VCSELs have been deployed in data centers for short-reach optical data links. However, there is a constant need to increase the link speed to accommodate the ever-growing data traffic. The dissertation will discuss operation physics, emerging challenges, and solutions in the development of VCSELs for 50 Gb/s NRZ data link over 100 meters OM4 fiber and operation up to 115 °C."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["High-speed oxide-VCSELS for optical data links in data center and cryogenic computing applications"]}]}],"canonical_facts":{"dc:contributor":["Feng, Milton","Jin, Jianming","Dragic, Peter D","Lee, Minjoo Lawrence"],"dc:creator":["Fu, Wenning"],"dc:date":["2023-05","2023-01-04"],"dc:description":["Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2025-05-01","The student, Wenning Fu, accepted the attached license on 2022-12-16 at 11:51.","The student, Wenning Fu, submitted this Dissertation for approval on 2022-12-16 at 12:21.","This Dissertation was approved for publication on 2023-01-04 at 13:36.","DSpace SAF Submission Ingestion Package generated from Vireo submission #18804 on 2023-09-01 at 17:12:16","In recent years, there is a growing demand for a high-speed and power-efficient data extraction from cryogenic environments, such as superconducting processors based on single flux quantum (SFQ) technology at 4 Kelvin (K). To achieve such data transfer from 4 K to room-temperature electronics, optical data links based on cryogenic VCSELs at 4 K or an intermediate temperature are promising solutions due to low signal loss and low heat leak in fibers. The main work demonstrated in this dissertation is the development of a record high-speed cryogenic VCSEL with optical data transmission over 50 Gb/s from liquid-nitrogen and liquid-helium temperature to room-temperature electronics. Furthermore, the bandwidth measurement, microwave modeling, and parameter extraction have indicated that the capability of the cryogenic VCSELs is far beyond 50 Gb/s data rate. The extracted intrinsic bandwidth of 88.7 GHz at liquid-nitrogen temperature projects to a 200 Gb/s, sub-100 fJ/bit single-VCSEL, single-fiber data link. Also reported is the first demonstration that superconducting circuits are used to modulate a fully packaged VCSEL for up to 20 Gb/s NRZ data transmission via a fiber link from 4 K all the way to room-temperature users. The data rate is limited by the superconducting processor available to use. The authors believe that this work paves the way for next-generation cryogenic computing technologies by solving one of the key issues: the need of a high-speed, efficient, and low-heat-leak data communication between cryogenic and room-temperature environments. To make a transition into the cryogenic VCSEL development chapter, room-temperature VCSEL development, which was partially contributed by the author, is presented first. For many years, room-temperature GaAs-based 850nm VCSELs have been deployed in data centers for short-reach optical data links. However, there is a constant need to increase the link speed to accommodate the ever-growing data traffic. The dissertation will discuss operation physics, emerging challenges, and solutions in the development of VCSELs for 50 Gb/s NRZ data link over 100 meters OM4 fiber and operation up to 115 °C."],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2142/120327"],"dc:language":["en","eng"],"dc:rights":["Copyright 2023 Wenning Fu"],"dc:subject":["High-speed Communication","Oxide Vcsels"],"dc:title":["High-speed oxide-VCSELS for optical data links in data center and cryogenic computing applications"],"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 at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:57Z"}