Abstract: Methods and apparatus for photodetection having parallax compensation for near and far object signal return. In embodiment, a photoreceiver comprising a at least one light-sensitive pixel to transduce light to electrical signals has at least a first one of the pixels including a first subpixel region having a first light response characteristic and a second subpixel region having a second light response characteristic, wherein the first and second light characteristics are configured to correspond to variations in intensity of reflected light from objects at different distances when the portion of the reflected light reaching the first one of the pixels imaged onto the first and second subpixel regions.

Abstract: Methods and apparatus for a system including an optic to receive light from near objects and far objects and a photoreceiver optically coupled to the optic, the photoreceiver including a photodetector array. A light scattering structure is positioned a distance from the photodetector array to compensate for parallax effects for the received energy from the near objects and the far objects. The light scattering structure is configured to scatter light onto pixels of the photodetector array.

Abstract: Methods and apparatus for a sensor having a photodetector array having photodetectors comprising a colloidal quantum dot (CQD) structure formed on an integrated circuit. The sensor may comprise a LIDAR time of flight sensor.

Abstract: Lidar transmission optics and systems project more laser pulse energy per pixel instantaneous field-of-view (IFOV) to a portion of a sensor field of view (FOV), e.g., a portion that would be expected to have both close and distant objects of interest, and proportionally less pulse energy per pixel IFOV to other portions of the sensor FOV, e.g., those that would be expected to have or see only close objects of interest. Optics such as diffractive optical elements (DOEs), gradient-index (GRIN) lenses, and/or compound lens systems can be used for producing desired irradiance distributions having multiple parts or regions. The optics and systems improve range performance by providing for more efficient use of the total available laser pulse energy than transmit optics that project uniform pulse energy per pixel IFOV across the sensor FOV.

Abstract: A method includes forming a plurality of identical arrays on a semiconductor wafer, each array having a plurality of detectors, screening each of the plurality of arrays to determine an operational status of each of the plurality of arrays, and selecting one of the plurality of arrays for use based on the determination of the operational status of the plurality of arrays. Also described is a focal plane array including a circuit having a plurality of electrical contacts and a die including a plurality of identical arrays, each including a plurality of detectors. The plurality of identical arrays includes at least one selected array that is fully functional and at least one non-selected array that is not fully functional and the selected array is positioned with respect to the circuit so that the detectors of the selected array contact the plurality of electrical contacts of the circuit.

Abstract: Methods and apparatus for nonuniformity correction (NUC) for a sensor having an avalanche photodiode (APD) array and an integrated circuit. The sensor can include anode bias control module, a passive mode module, and an active mode module. DC photocurrent from the APD array can be measured and used for controlling an anode reverse bias voltage to each element in the APD to achieve a nonuniformity correction level less than a selected threshold.

Abstract: Methods and apparatus for nonuniformity correction (NUC) for a sensor having an avalanche photodiode (APD) array and an integrated circuit. The sensor can include anode bias control module, a passive mode module, and an active mode module. DC photocurrent from the APD array can be measured and used for controlling an anode reverse bias voltage to each element in the APD to achieve a nonuniformity correction level less than a selected threshold.

Abstract: A method includes forming a plurality of identical arrays on a semiconductor wafer, each array having a plurality of detectors, screening each of the plurality of arrays to determine an operational status of each of the plurality of arrays, and selecting one of the plurality of arrays for use based on the determination of the operational status of the plurality of arrays. Also described is a focal plane array including a circuit having a plurality of electrical contacts and a die including a plurality of identical arrays, each including a plurality of detectors. The plurality of identical arrays includes at least one selected array that is fully functional and at least one non-selected array that is not fully functional and the selected array is positioned with respect to the circuit so that the detectors of the selected array contact the plurality of electrical contacts of the circuit.

Abstract: Methods and apparatus for compensating for bad pixels in a sensor array. In embodiments, a detector system receives an image on a sensor array of pixels for a first frame via a lens when the lens and the sensor array are configured in a first positional relationship. The array includes at least one bad pixel. The system moves the lens and/or the sensor array based on a position of the at least one bad pixel in the image such that the lens and the sensor array are configured in a second positional relationship. The image on the sensor array for a second frame is received via the lens when the lens and the sensor array are configured in a second positional relationship. The system compensates for the location of the at least one bad pixel in the image for the first and second frames to output a processed image.

Abstract: A composite quantum-dot photodetector comprising a substrate with a colloidally deposited thin film structure forming a photosensitive region, the thin film containing at least one type of a nanocrystal quantum-dot, whereby the nanocrystal quantum dots are spaced by ligands to form a lattice, and the lattice of the quantum dots has an infill material that forms an inorganic matrix that isolates the nanocrystal quantum dots from atmospheric exposure.

Abstract: A method of operating an avalanche photodiode includes providing an avalanche photodiode having a multiplication region capable of amplifying an electric current when subject to an electric field. The multiplication region, in operation, has a first ionization rate for electrons and a second, different, ionization rate for holes. The method also includes applying the electric field to the multiplication region, receiving a current output from the multiplication region, and varying the electric field in time, whereby a portion of the current output is suppressed.

Abstract: A composite quantum-dot photodetector comprising a substrate with a colloidally deposited thin film structure forming a photosensitive region, the thin film containing at least one type of a nanocrystal quantum-dot, whereby the nanocrystal quantum dots are spaced by ligands to form a lattice, and the lattice of the quantum dots has an infill material that forms an inorganic matrix that isolates the nanocrystal quantum dots from atmospheric exposure.

Abstract: A method of operating an avalanche photodiode includes providing an avalanche photodiode having a multiplication region capable of amplifying an electric current when subject to an electric field. The multiplication region, in operation, has a first ionization rate for electrons and a second, different, ionization rate for holes. The method also includes applying the electric field to the multiplication region, receiving a current output from the multiplication region, and varying the electric field in time, whereby a portion of the current output is suppressed.

Abstract: A method of operating an avalanche photodiode includes providing an avalanche photodiode having a multiplication region capable of amplifying an electric current when subject to an electric field. The multiplication region, in operation, has a first ionization rate for electrons and a second, different, ionization rate for holes. The method also includes applying the electric field to the multiplication region, receiving a current output from the multiplication region, and varying the electric field in time, whereby a portion of the current output is suppressed.

Abstract: The output of an avalanche photodiode (APD) comprises a “photocurrent” component comprising photon initiated events resulting from the interaction of photons with the APD and a “dark current” component comprising dark carrier events arising in the APD even when the APD is not exposed to light. Differences in the pulse height distributions of photon initiated events and dark carrier initiated events are used to statistically discriminate between photocurrent and dark current components of APD output.

Abstract: The output of an avalanche photodiode (APD) comprises a “photocurrent” component comprising photon initiated events resulting from the interaction of photons with the APD and a “dark current” component comprising dark carrier events arising in the APD even when the APD is not exposed to light. Differences in the pulse height distributions of photon initiated events and dark carrier initiated events are used to statistically discriminate between photocurrent and dark current components of APD output.

Abstract: An avalanche photodiode (APD) includes an anode layer, a cathode layer, an absorption layer between the anode layer and the cathode layer, a first multiplying stage between the absorption layer and the cathode layer, a second multiplying stage between the first multiplying stage and the cathode layer, and a carrier relaxation region between the first and second multiplying stages. Each multiplying stage includes, in the direction of drift of electrons, a first layer that is doped with acceptors, a second layer that is substantially undoped, a third layer that is doped with acceptors, a fourth layer that is substantially undoped, and a fifth layer that is doped with donors.