Abstract: Systems and methods are directed to determining the vacuum integrity within a vacuum package assembly containing an infrared detector, such as within an infrared imaging device. For example for an embodiment, a method of performing a vacuum pressure test on a vacuum package includes changing a first parameter value associated with an infrared detector within the vacuum package to vary a temperature of the infrared detector; measuring a second parameter value associated with the infrared detector based on the changing of the first parameter value; comparing the second parameter value to a threshold value; and determining a vacuum pressure condition of the vacuum package based on the comparing of the second parameter value to the threshold value.

Abstract: An improved detector assembly 10 having decreased sensitivity both to Narcissism and to stray light ghosting is disclosed herein. The improved detector assembly 10 of the present invention includes a housing 70 having an input aperture 142 in communication with a chamber within said housing. A detector 130 for sensing electromagnetic energy passing through the input aperture 142 within a first field of view is mounted within the chamber. Also mounted within the chamber is a detector mirror 100 for reflecting energy passing through the input aperture 142 within a second field of view outside of the first field of view. The improved assembly 10 of the present invention further includes a second mirror 110 mounted within the chamber for reflecting energy reflected by the first mirror 100 through the input aperture 142.

Abstract: A focal plane array (10) of radiation detectors (10b) has all features inclined with respect to an illuminating beam of radiation. That is, all features that would be orthogonally disposed with respect to an incoming wavefront are instead inclined to the incoming wavefront, an arrangement referred to as compound tipping. The disclosed embodiments of the invention create a compound tipping of the focal plane array such that there are no features of the array, such as mesa edges and sidewalls, that lie in the plane of the incoming wavefront. As a result, only a small amount of scattered light is observed, and the optical signature is significantly reduced. The invention substantially eliminates the optical signature by simultaneously tipping the focal plane features (optically and/or mechanically) in both major array axes, without degrading the imaging performance of the detective assembly.

Abstract: A radiation detector includes a photovoltaic diode mesa structure (16) having of a plurality of sub-mesa structures (16a, 16b). Each of said sub-mesa structures includes a first layer (14a) of semiconductor material having a first type of electrical conductivity and a second layer (14b) having a second type of electrical conductivity such that a p-n junction is formed between the first and the second layers. Metalization (24) is disposed within a trench (30a) that runs between the sub-mesas and includes a tab portion (24a) that extends upwardly over a sidewall of each of said sub-mesa structures so as to electrically contact the second layer contained within each. As a result, each of said sub-mesa structures are electrically connected in parallel.

Abstract: An IR detector array (10) wherein a metal contact pad (20) makes contact to an underlying radiation detector through one or more thin, electrically conductive stripes (20a). The striped pad contact shape is used in conjunction with a highly absorptive and opaque coating (18) that is interposed between a bottom surface of the contact pad and a top surface of the radiation detector. The highly absorptive coating serves to mask the bottom surface of the metal contact pad from any radiation that would impinge thereon and be reflected. As a result, stray or unabsorbed radiation reaching to a region of the contact pad encounters only the relatively small target presented by the edge of the one or more thin electrically conductive stripes.

Abstract: A radiation shield 40 is mounted to an uncooled portion, such as an outer case 14, of an IR detector assembly 10 such that it surrounds a thermoelectric cooler 16 and a radiation detector 18. The shield 40 has a curved reflective upper surface 42 having the shape of a toric segment and cylindrical or rectangular reflective sidewalls 44 for imaging the detector 18 and the upper cooler stage upon the tops and sides of lower and slightly warmer cooler stages, which absorb and eliminate radiative energy. This beneficially reduces the heat load upon the coldest stage by excluding hotter surfaces from its view, and by inhibiting reflective couplings of unwanted energy admitted by aperture 46. An aperture 46 defines the effective coldstop for the detector 18.