摘要 |
A device, for imaging infrared radiation from a scene, includes a detector of the infrared radiation, an enclosure for keeping the detector at an operating temperature thereof, an optical system, outside the enclosure, for focusing the infrared radiation onto the detector via a window of the enclosure, and a filter. In one embodiment, the filter is positioned at an intermediate focal plane of the optical system. In another embodiment, the filter is on a surface of an optical element of the optical system and has a defocusing relationship to the detector. |