An illuminator optical system combines, homogenizes, and shapes light spatially and angularly from one or more high power fiber coupled lasers. It may include a multichannel fiber cable, collimation and beam shaping optics, a multiple lens array (e.g., fly's eye lens array), and an objective lens. The multichannel fiber collects the light from the high power fiber coupled lasers and produces an aligned array of one or more optical fibers at the output of the cable. The light output from the cable is collimated and relayed to a multiple lens array that spatially divides and shapes the light into an array of beams. The objective lens homogenizes the light by collimating and overlapping the beams into a uniform top hat irradiance distribution in at least one dimension, resulting in the illumination pattern having the required spatial size and desired angular distribution at the illumination plane.