Vertical-cavity surface-emitting lasers for medical diagnosis

Thor Ansbæk

Research output: Book/ReportPh.D. thesisResearch

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Abstract

This thesis deals with the design and fabrication of tunable Vertical-Cavity Surface-Emitting Lasers (VCSELs). The focus has been the application of tunable VCSELs in medical diagnostics, specifically OCT. VCSELs are candidates as light sources for swept-source OCT where their high sweep rate, wide sweep range and high degree of coherence enable deep probing of tissue at acquisition rates that will eliminate the effects of rapid involuntary eye movements.
The main achievement of the dissertation work has been the development of an electro-statically tunable VCSEL at 1060 nm with wide tuning range and high tuning rate. The VCSEL is highly single-mode and inherently polarization stable due to the use of a High-index Contrast subwavelength Grating (HCG). HCG VCSELs are presented with 1.5% relative tuning range at a tuning rate of 850 kHz.
The thesis reports on the analysis of narrow linewidth Fabry-Pérot filters with dissimilar mirrors and the design of such Fabry-Pérot cavities for VCSELs. Fabrication of InGaAs multiple quantum wells with GaAsP strain balancing layers is covered together with the growth and wet chemical etching of InAlP. The fabrication of the proposed Fabry-Pérot filters and VCSELs is outlined and the results on their characterization reported.
Original languageEnglish
Place of PublicationKgs. Lyngby
PublisherTechnical University of Denmark
Number of pages95
ISBN (Print)87-92062-83-0
Publication statusPublished - 2012

Projects

VCSEL´S til medicinsk diagnosticering

Ansbæk, T., Yvind, K., Chung, I., Larsson, D., Hvam, J. M., Amann, M. C. & Birkedal, D.

Technical University of Denmark

01/11/200820/09/2012

Project: PhD

Cite this

Ansbæk, T. (2012). Vertical-cavity surface-emitting lasers for medical diagnosis. Technical University of Denmark.