An exposure system (5) for fabricating optical film (40) such as for photoalignment, where the optical film (40) has a photosensitive layer (20) and a substrate (10). The exposure system (5) directs an exposure beam from a light source (1) through the optical film (40), then uses a reflective surface (58) to reflect the exposure energy back through the optical film (40) to enhance or otherwise further condition the photoreaction of the photosensitive layer (20).