摘要 |
An optical sensing system which generally comprises an infrared sensor (12), and a curved diffraction-limited window (14) disposed in front of the sensor such that the optical axis (16) of the sensor is parallel to and displaced from the symmetry axis of the window. The window has an inner radius of curvature which is non-concentric with the outer radius of curvature in order to remove the optical power of the window. Additionally, the window is provided with an aspheric profile outer surface (20), in order to correct for spherical aberrations in the window. The window is made out of germanium and is particularly useful for a sensor which has an 8-12 micron infrared radiation detection band width. |