I investigate the use of vertical cavity surface emitting lasers (VCSELs) for portable optical neural imaging. In particular, I attempt to use one laser source to produce the different illumination needed for three techniques, imaging flow, oxygenation, and fluorescence. Our group's goal is to combine these techniques using a single source in a simple imaging format, which can be modified for portable use in awake animals. We exploit tuning properties of VCSELs to implement two distinct operation schemes with different illumination characteristics. Single mode operation provides high speckle contrasts, used to map flow speeds in laser speckle contrast imaging (LSCI). Sweep operation provides low noise, allowing us to image small signal changes with intrinsic optical signal imaging (IOSI), which relate to blood oxygenation. Finally, we use our VCSEL devices for on-chip integrated fluorescence sensing. Future work aims to develop a fully portable format, using CMOS detectors and integrated circuit control.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/31305 |
| Date | 14 December 2011 |
| Creators | Levy, Hart |
| Contributors | Levi, Ofer |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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