A spatial light modulator 100 comprising an array-type liquid crystal panel 115, a polarization beam splitter 120, an oblique wave plate 130 and a converging lens 135. The polarization beam splitter is orientated to direct a source light 125 towards a reflective planar surface 127 of the array-type liquid crystal panel. The oblique wave plate and converging lens are located between the polarization beam splitter and the array-type liquid crystal panel. The converging lens is configured to direct light from the reflective planar surface onto a facing surface 125 of the polarization beam splitter.