Abstract: Devices, systems, and methods are provided for reducing electrical and optical crosstalk in photodiodes. A photodiode may include a first layer with passive material, the passive material having no electric field. The photodiode may include a second layer with an absorbing material, the second layer above the first layer. The photodiode may include a diffused region with a buried p-n junction. The photodiode may include an active region with the buried p-n junction and having an electric field greater than zero. The photodiode may include a plateau structure based on etching through the second layer to the first layer, the etching performed at a distance of fifteen microns or less from the buried p-n junction.

Abstract: Systems and methods are described for optical processing. According to some aspects an apparatus may include a pixelated photodiode array (PDA), wherein each pixel in the PDA includes a radiation detector. The optical processing apparatus may also include a memory that stores one or more characteristics for each pixel in the PDA, and a read out integrated circuit (ROIC) communicatively coupled to the FPA and the memory. In some aspects, the ROIC reads from the memory the one or more characteristics for each pixel in the PDA, and adjusts an arm/disarm bias voltage for each pixel in the PDA based on the one or more characteristics of each pixel.

Abstract: Systems and methods are described for optical processing. According to some aspects an optical processing apparatus may include a pixelated photodiode array (PDA), each pixel in the PDA includes a radiation detector. The apparatus also includes a read out integrated circuit (ROIC) that includes a logic circuit and a plurality of switch elements. The plurality of switch elements being switchable between an armed state for arming its corresponding radiation detector and transmitting a signal received from the corresponding detector to the ROIC, and a disarmed state for disarming its corresponding detector and blocking transmittal of the signal, wherein in the armed state, the PDA is configured to detect an incoming optical signal and in the disarmed state, the PDA is configured to disregard the incoming optical signal. Moreover, the logic circuit controls a switch state of a selectable switch element associated with a radiation detector.

Abstract: A temporal pulse coding scheme is disclosed for use in operating pulsed lidar systems, and in particular, pulsed lidar systems used as sensors on autonomous vehicles. Pulse coding can be implemented to eliminate range ambiguity due to aliasing effects. Alternatively, pulse coding can be used with cyclic re-mapping to extend the maximum range of the lidar detector. Pulse coding can be further combined with arm coding to make range determinations over a continuous range having no dead zones.

Abstract: Devices, systems, and methods are provided for reducing electrical and optical crosstalk in photodiodes. A photodiode may include a first layer with passive material, the passive material having no electric field. The photodiode may include a second layer with an absorbing material, the second layer above the first layer. The photodiode may include a diffused region with a buried p-n junction. The photodiode may include an active region with the buried p-n junction and having an electric field greater than zero. The photodiode may include a plateau structure based on etching through the second layer to the first layer, the etching performed at a distance of fifteen microns or less from the buried p-n junction.

Abstract: Devices, systems, and methods are provided for reducing electrical and optical crosstalk in photodiodes. A photodiode may include a first layer with passive material, the passive material having no electric field. The photodiode may include a second layer with an absorbing material, the second layer above the first layer. The photodiode may include a diffused region with a buried p-n junction. The photodiode may include an active region with the buried p-n junction and having an electric field greater than zero. The photodiode may include a plateau structure based on etching through the second layer to the first layer, the etching performed at a distance of fifteen microns or less from the buried p-n junction.

Abstract: Devices, systems, and methods are provided for reducing electrical and optical crosstalk in photodiodes. A photodiode may include a first layer with passive material, the passive material having no electric field. The photodiode may include a second layer with an absorbing material, the second layer above the first layer. The photodiode may include a diffused region with a buried p-n junction. The photodiode may include an active region with the buried p-n junction and having an electric field greater than zero. The photodiode may include a plateau structure based on etching through the second layer to the first layer, the etching performed at a distance of fifteen microns or less from the buried p-n junction.

Abstract: A single-photon detector is disclosed that provides reduced afterpulsing without some of the disadvantages for doing so in the prior art. An embodiment of the present invention provides a stimulus pulse to the active area of an avalanche photodetector to stimulate charges that are trapped in energy trap states to detrap. In some embodiments of the present invention, the stimulus pulse is a thermal pulse.

Abstract: Avalanche photodiodes are provided, wherein the APDs provide both high optical coupling efficiency and low dark count rate. The APDs are formed such that their cap layer has an active region of sufficient width to enable high optical coupling efficiency but the APD still exhibits a low dark count rate. These cap layers have a device area with an active region and an edge region, wherein the size of the active region is substantially matched to the mode-field diameter of an optical beam, and wherein the size of the edge region is made small so as to reduce the number of defects included. These APD designs maintain a substantially uniform gain and breakdown voltage, as necessary for practical use.

Abstract: Methods for fabricating an avalanche photodiode (APD), wherein the APD provides both high optical coupling efficiency and low dark count rate. The APD is formed such that it provides an active region of sufficient width to enable high optical coupling efficiency and a low dark count rate. Some APDs fabricated using these methods have a device area with an active region and an edge region, wherein the size of the active region is substantially matched to the mode-field diameter of an optical beam, and wherein the size of the edge region is substantially minimized and further wherein the device region maintains a substantially uniform gain and breakdown voltage.

Abstract: An optical coupling assembly having an optical receiver that exhibits extended dynamic range, and, more particularly, an optical receiver that is integrated with a Variable Optical Attenuator (VOA) to extend the dynamic range of the receiver.

Abstract: An optical coupling assembly having an optical receiver that exhibits extended dynamic range, and, more particularly, an optical receiver that is integrated with a Variable Optical Attenuator (VOA) to extend the dynamic range of the receiver.

Abstract: A highly reflecting back illuminated diode structure allows light that has not been absorbed by a semiconductor absorbing region to be back reflected for at least a second pass into the absorbing region. The diode structure in a preferred embodiment provides a highly reflecting layer of gold to be supported in part by a conducting alloyed electrode ring contact and in part by a passivation layer of SixNy. Conveniently this structure provides a window within the contact which allows light to pass between the absorbing region and the reflecting layer of gold.

Abstract: A highly reflecting back illuminated diode structure allows light that has not been absorbed by a semiconductor absorbing region to be back reflected for at least a second pass into the absorbing region. The diode structure in a preferred embodiment provides a highly reflecting layer of gold to be supported in part by a conducting alloyed electrode ring contact and in part by a passivation layer of SixNy. Conveniently this structure provides a window within the contact which allows light to pass between the absorbing region and the reflecting layer of gold.

Abstract: A method for designing an avalanche photodiode for high bit rate or high speed applications is disclosed. The photodiode is made up of a multiplication layer of a first semiconductor material, an absorption layer of a second semiconductor material and a field control layer of a third semiconductor material having. The field control layer has a moderate doping of a first type dopant and is intermediate between the multiplication and absorption layers. A central region of the multiplication layer is diffused with a second type dopant which results in a diffused region having a greater thickness in the center than in the periphery of the diffused region.