Abstract: A two-terminal detector has a back-to-back p/n/p SWIR/MWIR stack structure, which includes P-SWIR absorber, N-SWIR, wide bandgap bather, N-MWIR absorber, and P-MWIR layers, with contacts on the P-MWIR and P-SWIR layers. The junction between the SWIR layers and the junction between the MWIR layers are preferably passivated. The detector stack is preferably arranged such that a negative bias applied to the top of the stack reverse-biases the MWIR junction and forward-biases the SWIR junction, such that the detector collects photocurrent from MWIR radiation. A positive bias forward-biases the MWIR junction and reverse-biases the SWIR junction, such that photocurrent from SWIR radiation is collected. A larger positive bias induces electron avalanche at the SWIR junction, thereby providing detector sensitivity sufficient to provide low light level passive amplified imaging. Detector sensitivity in this mode is preferably sufficient to provide high resolution 3-D eye-safe LADAR imaging.

Abstract: A substrate-removed, surface passivated, and anti-reflective (AR) coated detector assembly is provided. The assembly has an AR coating or passivation layer which includes a wide bandgap thin-film dielectric/passivation layer integrated therein. The wide bandgap thin-film dielectric/passivation layer is positioned proximal to a back interface of a substrate-removed detector assembly. A method of manufacturing the detector assembly includes etching a backside of a partially-removed-substrate detector assembly to obtain an etched detector assembly removed from a substrate. A wide bandgap layer is deposited, in a vacuum chamber, on the etched detector assembly without utilizing an adhesive layer. Additional anti-reflective coating layers are deposited, in the same vacuum chamber, on the wide bandgap layer to form an anti-reflective coating layer with the wide bandgap layer integrated therein.

Abstract: A two-terminal detector has a back-to-back p/n/p SWIR/MWIR stack structure, which includes P-SWIR absorber, N-SWIR, wide bandgap bather, N-MWIR absorber, and P-MWIR layers, with contacts on the P-MWIR and P-SWIR layers. The junction between the SWIR layers and the junction between the MWIR layers are preferably passivated. The detector stack is preferably arranged such that a negative bias applied to the top of the stack reverse-biases the MWIR junction and forward-biases the SWIR junction, such that the detector collects photocurrent from MWIR radiation. A positive bias forward-biases the MWIR junction and reverse-biases the SWIR junction, such that photocurrent from SWIR radiation is collected. A larger positive bias induces electron avalanche at the SWIR junction, thereby providing detector sensitivity sufficient to provide low light level passive amplified imaging. Detector sensitivity in this mode is preferably sufficient to provide high resolution 3-D eye-safe LADAR imaging.

Abstract: A substrate-removed, surface passivated, and anti-reflective (AR) coated detector assembly is provided. The assembly has an AR coating or passivation layer which includes a wide bandgap thin-film dielectric/passivation layer integrated therein. The wide bandgap thin-film dielectric/passivation layer is positioned proximal to a back interface of a substrate-removed detector assembly. A method of manufacturing the detector assembly includes etching a backside of a partially-removed-substrate detector assembly to obtain an etched detector assembly removed from a substrate. A wide bandgap layer is deposited, in a vacuum chamber, on the etched detector assembly without utilizing an adhesive layer. Additional anti-reflective coating layers are deposited, in the same vacuum chamber, on the wide bandgap layer to form an anti-reflective coating layer with the wide bandgap layer integrated therein.

Abstract: A fully depleted “diode passivation active passivation architecture” (DPAPA) produces a photodiode structure which includes a substrate, a highly-doped buffer layer of a first carrier doping type above the substrate, a low-doped or undoped semiconductor active layer of the first carrier doping type above the buffer layer, a low-doped or undoped passivation layer above the active layer, the passivation layer having a wider band gap than the active layer; and a junction layer of a carrier doping type opposite the first carrier doping type above the passivation layer such that a pn junction is formed between the junction layer and the passivation and active layers, the junction creating a depletion region which expands completely through the passivation and active layers in response to a reverse bias voltage. The fully depleted structure substantially eliminates Auger recombination, reduces dark currents and enables cryogenic level performance at high temperatures.

Abstract: A cost-effective FPA includes a plurality of detectors per pixel, wherein radiation is directed by a microlens array into respective focal regions that are covered by the union of the detectors' collections regions within each pixel and any defective detectors are de-selected in the ROIC. The operability of each pixel is evaluated, and a map generated specifying detector de-selection for each pixel. This map is read into memory in the ROIC to de-select bad detectors. Bad detectors are preferably allowed to float to a photovoltage and re-emit some of their accumulated photo charge to neighboring detectors to improve collection efficiency. The radiation levels are preferably read out on a pixel-by-pixel basis. Accordingly, the signals from the selected detectors are combined within each pixel.

Abstract: The present invention provides a heterojunction photodiode which includes a pn or Schottky-barrier junction formed in a first material region having a bandgap energy Eg1. When reverse-biased, the junction creates a depletion region which expands towards a second material region having a bandgap energy Eg2 which is less than Eg1. This facilitates signal photocurrent generated in the second region to flow efficiently through the junction in the first region while minimizing the process-related dark currents and associated noise due to near junction defects and imperfect surfaces which typically reduce photodiode device performance. The heterojunction photodiode can be included in an imaging system which includes an array of junctions to form an imager.

Abstract: A photodetector includes a charge carrier collector and a charge carrier concentrator that redirects onto the collector charge carriers that are not initially headed towards the collector.

Abstract: An infrared energy detection apparatus having a first array of infrared detectors adapted to detect infrared energy of a first wavelength and produce an electrical signal corresponding to such detected energy, and a second array of infrared detectors, positioned to intercept infrared energy passing through the first array, and adapted to detect energy of a second wavelength in such intercepted energy and produce an electrical signal corresponding to such detected energy. The first array of infrared detectors includes an array of detector devices formed along a lower portion thereof adapted to detect a portion of radiation impinging on the upper portion thereof and, electronic circuitry disposed between the upper and lower portions and connected to the detector devices for producing electrical signals representative of the detected energy having the first wavelength.

Abstract: A piezoelectric wafer of single crystal berlinite, having a surface defined by an X-axis boule cut at an angle in the range from about 94.degree.-104.degree., provides an improved substrate for a surface acoustic wave device. These cut angles are relatively easy to fabricate, provide excellent temperature compensation in a range from -55.degree. C. to 125.degree. C., and have high piezoelectric coupling coefficient.

Abstract: A piezoelectric wafer of single crystal berlinite, having a surface defined by an X-axis boule cut at about 85.degree., provides a improved substrate for a surface acoustic wave device. The 85.degree. cut angle is relatively easy to fabricate, provides excellent temperature compensation in a range form 20.degree. C. to 100.degree. C., and has high piezoelectric coupling coefficient.