| 摘要 |
Co-aligning a plurality of radiation beams 10 each having a respective waveband is achieved by passing the beams 10 to an optical collimating element 14 and then passing the beams 10 to an optical deflecting element 16 to cause the beams 10 to become co-aligned. At least one of the elements 14, 16 has an anti-reflection layer (19, fig 2a) for minimising reflection of the beams 10 from the element 14, 16. The layer has an array of microstructured protuberances (20, fig 2a) which extend away from a surface of the element 14, 16, and have a cross sectional area which reduces along the length, from a proximal end to a distal end. |
