Vertical cavity surface emitting laser based on GaAs/air-gap distributed Bragg reflectors: from concept to working devices

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dc.contributor.advisorDeppe, Dennis G.en
dc.creatorMo, Qingweien
dc.date.accessioned2008-08-28T21:58:03Zen
dc.date.accessioned2017-05-11T22:16:25Z
dc.date.available2008-08-28T21:58:03Zen
dc.date.available2017-05-11T22:16:25Z
dc.date.issued2004en
dc.descriptiontexten
dc.description.abstractVertical-cavity surface-emitting lasers (VCSELs) have created new opportunities in optoelectronics. However, VCSELs have so far been commercialized mainly for operation at 0.85 µm, despite their potential importance at other wavelengths, such as 1.3 µm and 1.55 µm. The limitations at these longer wavelengths come from material characteristics, such as a low contrast ratio in mirror materials, lower mirror reflectivity, and smaller optical gain for longer wavelength materials versus AlGaAs/GaAs quantum wells. A similar situation, insufficient gain relative to the cavity loss, existed in the past for shorter wavelength VCSELs before high quality epitaxial mirrors were developed. Semiconductor/air-gap Distributed Bragg Reflectors (DBRs) are attractive due to their high index contrast, which leads to a high reflectivity, wide stop band and low optical loss mirror with a small number of pairs. This concept is ready to be integrated into material systems other than AlGaAs/GaAs, which is studied in this work. Therefore, the impact of these DBRs can be extended into both visible and longer infrared wavelengths as a solution to the trade-off between DBR and active region materials. Air-gap DBRs can also be used as basic building blocks of micro-opto-electro-mechanical systems (MOEMS). The high Q microcavity formed by the air-gap DBRs also provide a good platform for microcavity physics study. Air-gap DBRs are modeled using the transmission matrix formulae of the Maxwell equations. A comparison to existing DBR technology shows the great advantage and potential that the air-gap DBR possesses. Two types of air-gap are proposed and developed. The first one includes multiple GaAs/air pairs while the second one combines a single air-gap with metal and dielectric mirrors. New device structures and processing designs, especially an all-epitaxial lateral current and optical confinement technique, are carried out to incorporate air-gap DBRs into VCSEL structures. The first VCSEL based on a GaAs/air-gap DBR is successfully demonstrated. Low threshold continuous-wave lasing is achieved at room temperature. The device characteristics and air-gap DBR loss are analyzed based on experimental data.
dc.description.departmentElectrical and Computer Engineeringen
dc.format.mediumelectronicen
dc.identifierb59340381en
dc.identifier.oclc58389461en
dc.identifier.proqst3150699en
dc.identifier.urihttp://hdl.handle.net/2152/1375en
dc.language.isoengen
dc.rightsCopyright is held by the author. Presentation of this material on the Libraries' web site by University Libraries, The University of Texas at Austin was made possible under a limited license grant from the author who has retained all copyrights in the works.en
dc.subject.lcshOptoelectronic devicesen
dc.titleVertical cavity surface emitting laser based on GaAs/air-gap distributed Bragg reflectors: from concept to working devicesen
dc.type.genreThesisen

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