| 摘要 |
<p>A lens system for imaging infra-red radiation comprises two elements, one of Zinc Selenide 1 and the other of either Zinc Sulphide (2) or Caesium Bromide (5). Lens configurations are shown which allow imaging at a common image plane (4) over at least both the 3-5 mu m and 8-12 mu m optical wavebands.</p> |
