Abstract: According to one aspect, embodiments herein provide a digital unit cell comprising a photodiode, an integration capacitor coupled to the photodiode and configured to accumulate charge generated by the photodiode responsive to an input light signal incident on the photodiode over an integration period, a comparator coupled to the integration capacitor and configured to compare a voltage across the integration capacitor with a voltage reference and to generate a clock signal at a first level each time a determination is made that the voltage across the integration capacitor is greater than the voltage reference, a shift register coupled to the comparator and configured to receive the clock signal from the comparator and increase a count value each time the clock signal at the first level is received from the comparator, and an output coupled to the shift register and configured to provide the count value to an external system.

Abstract: According to one aspect, embodiments herein provide a digital unit cell comprising a photodiode, an integration capacitor coupled to the photodiode and configured to accumulate charge generated by the photodiode responsive to an input light signal incident on the photodiode over an integration period, a comparator coupled to the integration capacitor and configured to compare a voltage across the integration capacitor with a voltage reference and to generate a clock signal at a first level each time a determination is made that the voltage across the integration capacitor is greater than the voltage reference, a shift register coupled to the comparator and configured to receive the clock signal from the comparator and increase a count value each time the clock signal at the first level is received from the comparator, and an output coupled to the shift register and configured to provide the count value to an external system.

Abstract: Dual-pupil, dual spectral band wide field-of-view re-imaged refractive optical imaging systems. In one example an optical imaging system includes a dual-band front objective lens group configured to receive electromagnetic radiation over the field-of-view of the optical imaging system, to form a first pupil, and to direct the electromagnetic radiation through the first pupil, the electromagnetic radiation including first and second non-overlapping spectral bands, and the field-of-view spanning at least 45°×45°, and a re-imaging refractive optical sub-system configured to receive the electromagnetic radiation via the first pupil, to form at least one intermediate image plane, and to focus the electromagnetic radiation via at least one second pupil onto at least one final image plane to form a first image from the first spectral band and a second image from the second spectral band. A beam deflector can be positioned proximate the first pupil to expand the field of view.

Abstract: Dual-pupil, dual spectral band wide field-of-view re-imaged refractive optical imaging systems. In one example an optical imaging system includes a dual-band front objective lens group configured to receive electromagnetic radiation over the field-of-view of the optical imaging system, to form a first pupil, and to direct the electromagnetic radiation through the first pupil, the electromagnetic radiation including first and second non-overlapping spectral bands, and the field-of-view spanning at least 45°×45°, and a re-imaging refractive optical sub-system configured to receive the electromagnetic radiation via the first pupil, to form at least one intermediate image plane, and to focus the electromagnetic radiation via at least one second pupil onto at least one final image plane to form a first image from the first spectral band and a second image from the second spectral band. A beam deflector can be positioned proximate the first pupil to expand the field of view.

Abstract: According to one embodiment, a computing system includes two or more opto-electrical isolators coupling a corresponding two or more memory devices to a processor. Each memory device is electrically isolated from each other and configured to store data or instructions executed by the processor. Each opto-electrical isolator selectively couples its associated memory device to the processor such that only one of the two or more memory devices are writable by the processor at any instant of time.

Abstract: An apparatus for multi-spectral imaging includes a microbolometer array comprising a two-dimensional array of microbolometer detectors that are configured to respond to energy having a first range of wavelengths comprising a first plurality of spectral bands. The apparatus also includes a wideband window configured to allow energy having a second range of wavelengths to reach the microbolometer array. The second range of wavelengths comprises a second plurality of spectral bands. The apparatus additionally includes optics configured to focus the energy from a scene towards the microbolometer array. The apparatus further includes a processor configured to generate an output based on a response of the microbolometer array to energy having a third range of wavelengths comprising a third plurality of spectral bands. There is substantial overlap between the first, second, and third range of wavelengths and the first, second, and third plurality of spectral bands.

Abstract: An apparatus for multi-spectral imaging includes a microbolometer array comprising a two-dimensional array of microbolometer detectors that are configured to respond to energy having a first range of wavelengths comprising a first plurality of spectral bands. The apparatus also includes a wideband window configured to allow energy having a second range of wavelengths to reach the microbolometer array. The second range of wavelengths comprises a second plurality of spectral bands. The apparatus additionally includes optics configured to focus the energy from a scene towards the microbolometer array. The apparatus further includes a processor configured to generate an output based on a response of the microbolometer array to energy having a third range of wavelengths comprising a third plurality of spectral bands. There is substantial overlap between the first, second, and third range of wavelengths and the first, second, and third plurality of spectral bands.

Abstract: According to one embodiment, a computing system includes two or more opto-electrical isolators coupling a corresponding two or more memory devices to a processor. Each memory device is electrically isolated from each other and configured to store data or instructions executed by the processor. Each opto-electrical isolator selectively couples its associated memory device to the processor such that only one of the two or more memory devices are writable by the processor at any instant of time.

Abstract: Multi-spectral images are detected using a refractive objective lens system. Magnesium oxide (MgO) and calcium fluoride (CaF2) lenses are used to image scenes in both the visible and infra-red (IR) spectrums. The inventors have discovered that the combination of magnesium oxide, only recently made available in a pure crystal form, and calcium fluoride can be used to fabricate an objective lens for imaging objects in both the visible and infra-red spectrums. Moreover, the combination of magnesium oxide and calcium fluoride results in a super-achromatic condition across visible and infra-red spectrums. This chromatically-corrected spectral range includes wavelengths between 0.4 and 5.9 microns which covers medium-wave IR (MWIR), short-wave IR (SWIR), and the near-IR/visible windows. Combinations of MgO and CaF2 lenses are used in different compound objective lens designs including doublet, Petzval, inverted telephoto, and telephoto arrangements.

Abstract: Multi-spectral images are detected using a refractive objective lens system. Magnesium oxide (MgO) and calcium fluoride (CaF.sub.2) lenses are used to image scenes in both the visible and infra-red (IR) spectrums. The inventors have discovered that the combination of magnesium oxide, only recently made available in a pure crystal form, and calcium fluoride can be used to fabricate an objective lens for imaging objects in both the visible and infra-red spectrums. Moreover, the combination of magnesium oxide and calcium fluoride results in a super-achromatic condition across visible and infra-red spectrums. This chromatically-corrected spectral range includes wavelengths between 0.4 and 5.9 microns which covers medium-wave IR (MWIR), short-wave IR (SWIR), and the near-IR/visible windows. Combinations of MgO and CaF.sub.2 lenses are used in different compound objective lens designs including doublet, Petzval, inverted telephoto, and telephoto arrangements.