Abstract
Nowadays, Vertical-Cavity Surface-Emitting Lasers (VCSELs) are the most popular optical sources in short-reach data communications. In the commercial oxide VCSEL technology, an oxide aperture is created inside resonant cavity in realizing good mode and current confinement, however, high electrical resistance comes along with forming the oxide aperture and the electrical parasitic bandwidth becomes the main limitation in modulation speed. In this report, electrical bandwidths of oxide-free lithographic VCSELs have been studied along with their general lasing properties. Due to the new ways of fabricating the aperture, record low resistances have been achieved in oxide-free lithographic VCSELs with various sizes, while high slope efficiencies and high output powers have been maintained. High speed simulation has been performed showing the very low differential resistances will benefit much to the electrical parasitic bandwidths, and are expected to produce higher modulation speed. A bottom emitting structure has been proposed and analyzed, showing reduction in both mirror resistance and capacitance will further improve the modulation speed. The total 3-dB modulation bandwidth is expected to be 50-80 GHz, much higher than the bandwidth reached in existing oxide VCSELs. Lithographic VCSELs also show superior lasing characteristics, including record low thermal resistance and record high output power. The maximum power exceeds 19 mW in a 6 µm device and over 50 % power conversion efficiency has been achieved. A maximum single mode operation power of 5 mW has been observed from a 1 µm diameter VCSEL. High temperature stress testing has been performed showing lithographic VCSELs can operate more reliably than oxide VCSELs under extreme operating conditions. Lithographic VCSEL with low electrical resistance, single-mode operation, high efficiency, and high power will be a strong candidate as the optical source in high speed data communications, as well as other applications such as high power VCSEL arrays and optical sensing.
Notes
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Graduation Date
2016
Semester
Summer
Advisor
Deppe, Dennis
Degree
Doctor of Philosophy (Ph.D.)
College
College of Optics and Photonics
Department
Optics and Photonics
Degree Program
Optics and Photonics
Format
application/pdf
Identifier
CFE0006425
URL
http://purl.fcla.edu/fcla/etd/CFE0006425
Language
English
Release Date
August 2019
Length of Campus-only Access
3 years
Access Status
Doctoral Dissertation (Open Access)
STARS Citation
Yang, Xu, "Electrical Parasitic Bandwidth Limitations of Oxide-Free Lithographic Vertical-Cavity Surface-Emitting Lasers" (2016). Electronic Theses and Dissertations. 5205.
https://stars.library.ucf.edu/etd/5205