| 摘要 |
A method and apparatus for providing a purged optical path between an optical source surface and an optical target surface and for permitting relative movement between the optical source surface and the optical target surface is described. The apparatus includes a body, a central cavity, at least one gas supply bore, and at least one gas removal bore. The body defines first and second opposing surfaces. The first opposing surface is configured for positioning closely adjacent to the optical target surface. The second opposing surface is configured to mate with the optical source surface. The central cavity is formed in the body for passing light through the body, the central cavity being open at the first and second opposing surfaces. The at least one gas supply bore is formed in the body for suppling a flow of a purge gas to the central cavity. The at least one gas removal bore is formed in the body at the first opposing surface to remove gas from a gap formed between the first opposing surface and the optical target surface. |
