| 摘要 |
<p>The infra-red objective is for the 8-12 micrometre wavelength range. It comprises three lenses (R1,2, R3,4, R5,6) of which one (R1,2) is germanium, one (R5,6) is arsenic trisulphide, and one (R3,4) is chalcogenide glass such as is known under trade names 19 1173 (Texas instruments) or Amtir 1 (Amorphous Materials Inc.). Dimensional details are specified for two examples of objectives with focal length 250. The lens has less chromatic aberration than prior art lenses.</p> |
