Applications of Fourier Domain Mode Locked lasers for optical coherence tomography imaging

Optical coherence tomography (OCT) is a micrometer-resolution imaging technique that produces cross-sectional images of sample microstructure by measuring the amplitude and echo time delay of backscattered light. OCT imaging is performed using low-coherence interferometry, typically with a fiber optic Michelson interferometer. OCT imaging has recently been performed by measuring the spectrum of the interference signal in the Fourier domain. In "swept source OCT" implementations, the interference spectra are generated with a wavelength-swept laser and photodetector. Axial image lines are obtained via Fourier transformation of the spectra. Fourier domain techniques have extended OCT imaging speeds from several thousand to hundreds of thousands of axial lines per second, enabling in vivo three-dimensional (3D) OCT. Development of the Fourier Domain Mode Locked (FDML) laser has significantly improved the imaging performance of swept source OCT by providing an unparalleled combination of high sweep rates, large tuning ranges, narrow instantaneous linewidths, and low phase noise. This thesis develops a number of advanced OCT imaging applications using FDML laser technology. Ultrahigh-speed sub-nanometer phase profilometry is performed by measuring the phase of the OCT interference signal, taking advantage of the inherent phase stability of FDML lasers. Extending this concept, phase-sensitive OCT is used to detect gold nanoshell contrast agents with extremely high signal-to-noise ratios by inducing photothermal phase modulations in the sample.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2009

Author dc:creator

• Adler, Desmond Christopher, 1978-

Advisor dc:contributor.advisor

• James G. Fujimoto.

• Electrical Engineering and Computer Science.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/53189

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/53189