Method and apparatus for illuminating and imaging tissue is provided. In one version, the method includes illuminating a volume of a tissue with photons from a three-dimensional array of optical emitters inserted into the tissue. In another version, the method includes detecting photons from a volume of a tissue using a three-dimensional array of optical detectors inserted into the tissue. A probe device for illuminating tissue and/or detecting photons emitted from tissue includes elongated microsized probes containing optical emitters and optical detectors in a three dimensional array.
