The present invention relates, in one aspect to an image replication system comprising a light guide (2), a light source (8) arranged to direct emitted light into the first end (2a) of a light guide (2), a reflective spatial light modulator (6) and focussing means (16). In a preferred embodiment, the light guide (2) is in the form of an elongate glass rod having first and second parallel polygonal end faces (2a, 2b) which are parallel to the long axis of the rod, the rod having a uniform polygonal cross section along its length. The spatial light modulator (6) is optically coupled to the second end face (2b) of the light guide (2) and the focussing means (16) is arranged to receive light reflected back through the rod from the spatial light modulator (6), whereby to form multiple images of said spatial light modulator in an image plane (18).