An optical image amplifier comprising a copper bromide laser (10) to provide a source of optical radiation, an optical amplifier (18) for amplifying the optical radiation received from the laser (10), an optical image forming device (16) located intermediate the laser (10) and optical amplifier (18) for forming an image to spatially modulate the output of the laser (10), and optical focusing means (22) located at the output of the optical amplifier for translating the image or a portion thereof to a surface to be illuminated (30). The system increases the efficiency of irradiation of photo-sensitive films, used for example in the manufacture of integrated circuits and printed circuit boards using laser direct imaging.