INFRATED DETECTOR DEVICES

摘要

In an infrared detector device for viewing an object or scene at more than one wavelength, the detector elements (10 and 20) are optimised to have appropriately different infrared responses by being formed in accordance with the invention in different levels (1 and 2) of different material on a substrate (3). Infrared concentrators (55) such as immersion lenses, light-pipes and/or reflectors collect incident radiation (50) over an area larger than the active portion of the associated detector element (10 and/or 20) and concentrate the radiation (50) onto the active portions. The arrangement adopted in accordance with the invention provides adequate space for at least one connection (15) of each upper-level detector element (10) to extend to the substrate (3) through an area of the lower level (2) which is located between the lower-level active portions on which the radiation (50) is concentrated by the associated concentrators (55). This upper-level connection (15) may extend via an island (28) separated from the active portions (22,23) of the lower level (2) by a gap (40), or it may extend on a side-wall of the lower-level detector element (20) when this side-wall is insulated or separated by a p-n junction from the active portions of the detector element (20). The different-response elements (10 and 20) may be arranged one above the other or one between the others when viewed in plan view.