A spatio-temporally incremental fiber sweep source includes a laser light pulse generator for generating light pulses and a fiber array (24) of individual optical fibers. The fiber array (24) has an input end (21) and an output end (23), with the fibers at the input end (21) receiving the light pulses substantially simultaneously. The optical fibers at the output end (23) are arranged in a raster scan pattern, e.g., a square pattern, wherein the optical delay in each fiber is greater than the previous one in the scan pattern direction. As a result light exits the array (24) in a completely optical two dimensional raster scan pattern. It has no moving parts, and thus no mechanical inertia, so extremely high speed scanning can be achieved.