Light is collected from a sample that is to be imaged, such as tissue or the like, and made to undergo self-interference, e.g., on a detector. An imaging system may include a low coherence light source arranged for illuminating the sample, and an interferometer arranged to receive the light collected from the sample and to pass it to a detector. The interferometer includes a beam divider that directs the radiation collected from the sample along two paths, phase-delaying one beam relative to another and then recombining the beams on a detector. A processor may be coordinated with the phase delay and in some embodiments with spatial scanning or detector array addresses, and operates on the signal from the detector to form a tomographic image of the sample illuminated tissue. By constructing an image based upon interference the interferometric signal from of the split and then recombined radiation collected from the sample signal, rather than interference of a source reference and a return signal, the invention is able to image with light naturally emitted by the sample, or with wavelength-shifted, delayed or induced light signals of different types, allowing new modalities of diagnostic and other imaging of the sample and its structure. A processor generates one or more images of the structure being viewed, and may create images in registry from different (for example, close but separable) wavelengths. Some systems may operate without an illumination source or may apply other stimuli to evoke emission from the sample.
