SYSTEM AND METHOD FOR OPTICAL IMAGING WITH VERTICAL CAVITY SURFACE EMITTING LASERS

The present invention uses vertical-cavity surface-emitting lasers (VCSELs) as illumination source for simultaneous imaging of blood flow and tissue oxygenation dynamics in vivo, or a means to monitor neural activity in brain slices ex vivo. The speckle pattern on the brain tissue due to a VCSEL's coherence properties is the main challenge to producing low-noise high-brightness illumination, required for evaluating tissue oxygenation. Moreover, using oxide-confined VCSELs we show a fast switching from a single-mode operation scheme to a special multi-modal, multi-wavelength rapid sweep scheme. The multi-modal, multi-wavelength rapid sweep scheme reduces noise values to within a factor of 40% compared to non-coherent LED illumination, enabling high-brightness VCSELs to act as efficient miniature light sources for various brain imaging modalities and other imaging applications. These VCSELs are promising for long-term portable continuous monitoring of brain dynamics in freely moving animals.