Multi-modality optical neural imaging using coherence control of VCSELs.

Neural optical imaging can evaluate cortical hemodynamic fluctuations which reflect neural activity and disease state. We evaluate the use of vertical-cavity surface-emitting lasers (VCSELs) as illumination source for simultaneous imaging of blood flow and tissue oxygenation dynamics ex vivo and in vivo and demonstrate optical imaging of blood flow changes and oxygenation changes in response to induced ischemia. Using VCSELs we show a rapid switching from a single-mode to a special multi-mode rapid current sweep operation and noise values reduced to within a factor of 40% compared to non-coherent LED illumination. These VCSELs are promising for long-term portable continuous monitoring of brain dynamics in freely moving animals.