Date of Award
MS in Electrical Engineering
Swept Source Optical Coherence Tomography (SS-OCT) is a medical imaging technique that requires high repetition rate, widely-tunable coherent laser sources. Sampled grating distributed Bragg reflector (SG-DBR) lasers are proven in telecom applications and are expected to fulfill the requirements for SS-OCT at a significantly lower cost than alternative solutions.
Constructed entirely on a semiconductor substrate, SG-DBR lasers require four synchronized waveforms to modulate the output wavelength and intensity. Because of this unique tuning mechanism, there are a number of systematic and noise sources that can affect the quality of the OCT point-spread function (PSF). Based on these noise sources, software is developed to simulate the waveforms in an SS-OCT system and determine the factors that limit width of the PSF central peak and the broadband skirts. Design curves are then created to specify the requirements to obtain a given performance.
Next, experimental tests are performed on a JDS Uniphase C-band SG-DBR laser to assess its performance limitations. Finally, by comparing theory and experiment, recommendations are made on acceptable systematic and random noise errors induced in the PSF.