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Lithographic Vertical-Cavity Surface-Emitting Lasers

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Date Issued:
2012
Abstract/Description:
Remarkable improvements in vertical-cavity surface-emitting lasers (VCSELs) have been made by the introduction of mode- and current-confining oxide optical aperture now used commercially. However, the oxide aperture blocks heat flow inside the device, causing a larger thermal resistance, and the internal strain caused by the oxide can degrade device reliability, also the diffusion process used for the oxide formation can limit device uniformity and scalability.Oxide-free lithographic VCSELs are introduced to overcome these device limitations, with both the mode and current confined within the lithographically defined intracavity mesa, scaling and mass production of small size device could be possible. The 3 ?m diameter lithographic VCSEL shows a threshold current of 260 ?A, differential quantum efficiency of 60% and maximum output power density of 65 kW/cm2, and shows single-mode single-polarization operation with side-mode-suppression-ratio over 25 dB at output power up to 1 mW. The device also shows reliable operation during 1000 hours stress test with high injection current density of 142 kA/cm2. The lithographic VCSELs have much lower thermal resistance than oxide-confined VCSELs due to elimination of the oxide aperture. The improved thermal property allows the device to have wide operating temperature range of up to 190 (&)deg;C heat sink temperature, high output power density especially in small device, high rollover current density and high rollover cavity temperature. Research is still underway to reduce the operating voltage of lithographic VCSELs for high wall plug efficiency, and the voltage of 6 (&)#181;m device at injection current density of 10 kA/cm2 is reduces to 1.83 V with optimized mesa and DBR mirror structure. The lithographic VCSELS are promising to become the next generation VCSEL technology.
Title: Lithographic Vertical-Cavity Surface-Emitting Lasers.
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Name(s): Zhao, Guowei, Author
Deppe, Dennis, Committee Chair
Likamwa, Patrick, Committee Member
Fathpour, Sasan, Committee Member
Sundaram, Kalpathy, Committee Member
University of Central Florida, Degree Grantor
Type of Resource: text
Date Issued: 2012
Publisher: University of Central Florida
Language(s): English
Abstract/Description: Remarkable improvements in vertical-cavity surface-emitting lasers (VCSELs) have been made by the introduction of mode- and current-confining oxide optical aperture now used commercially. However, the oxide aperture blocks heat flow inside the device, causing a larger thermal resistance, and the internal strain caused by the oxide can degrade device reliability, also the diffusion process used for the oxide formation can limit device uniformity and scalability.Oxide-free lithographic VCSELs are introduced to overcome these device limitations, with both the mode and current confined within the lithographically defined intracavity mesa, scaling and mass production of small size device could be possible. The 3 ?m diameter lithographic VCSEL shows a threshold current of 260 ?A, differential quantum efficiency of 60% and maximum output power density of 65 kW/cm2, and shows single-mode single-polarization operation with side-mode-suppression-ratio over 25 dB at output power up to 1 mW. The device also shows reliable operation during 1000 hours stress test with high injection current density of 142 kA/cm2. The lithographic VCSELs have much lower thermal resistance than oxide-confined VCSELs due to elimination of the oxide aperture. The improved thermal property allows the device to have wide operating temperature range of up to 190 (&)deg;C heat sink temperature, high output power density especially in small device, high rollover current density and high rollover cavity temperature. Research is still underway to reduce the operating voltage of lithographic VCSELs for high wall plug efficiency, and the voltage of 6 (&)#181;m device at injection current density of 10 kA/cm2 is reduces to 1.83 V with optimized mesa and DBR mirror structure. The lithographic VCSELS are promising to become the next generation VCSEL technology.
Identifier: CFE0004634 (IID), ucf:49912 (fedora)
Note(s): 2012-08-01
Ph.D.
Optics and Photonics, Optics and Photonics
Doctoral
This record was generated from author submitted information.
Subject(s): VCSEL -- lithographic -- oxide-free
Persistent Link to This Record: http://purl.flvc.org/ucf/fd/CFE0004634
Restrictions on Access: public 2013-02-15
Host Institution: UCF

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