Abstract: A method of fabricating a frontside-illuminated inverted quantum well infrared photodetector may include providing a quantum well wafer having a bulk substrate layer and a quantum material layer, wherein the quantum material layer includes a plurality of alternating quantum well layers and barrier layers epitaxially grown on the bulk substrate layer. The method further includes applying at least one frontside common electrical contact to a frontside of the quantum well wafer, bonding a transparent substrate to the frontside of the quantum well wafer, thinning the bulk substrate layer of the quantum well wafer, and etching the quantum material layer to form quantum well facets that define at least one pyramidal quantum well stack. A backside electrical contact may be applied to the pyramidal quantum well stack. In one embodiment, a plurality of quantum well stacks is bonded to a read-out integrated circuit of a focal plane array.

Abstract: Panoramic imaging systems including rotatable minors are provided. A panoramic imaging system includes a rotatable platform, an imaging device mounted to the rotatable platform, and a minor rotatably mounted to the rotatable platform. The mirror is positioned in an optical path of the imaging device. The mirror and the imaging device are oriented such that the minor and imaging device are in the same plane, an optical axis of the imaging device is substantially perpendicular to an axis of rotation of the rotatable platform, and an axis of rotation of the minor is substantially parallel to the axis of rotation of the rotatable platform when the mirror is in an initial position.

Abstract: Frontside-illuminated barrier infrared photodetector devices and methods of fabrication are disclosed. In one embodiment, a frontside-illuminated barrier infrared photodetector includes a transparent carrier substrate, and a plurality of pixels. Each pixel of the plurality of pixels includes an absorber layer, a barrier layer on the absorber layer, a collector layer on the barrier layer, and a backside electrical contact coupled to the absorber layer. Each pixel has a frontside and a backside. The absorber layer and the barrier layer are non-continuous across the plurality of pixels, and the barrier layer of each pixel is closer to a scene than the absorber layer of each pixel. A plurality of frontside common electrical contacts is coupled to the frontside of the plurality of pixels, wherein the frontside of the plurality of pixels and the plurality of frontside common electrical contacts are bonded to the transparent carrier substrate.

Abstract: Included are embodiments for enhanced carrier suppression. One embodiment of a circuit includes a mixer that receives a cover sequence, the cover sequence including transition data from a first signal and a second signal. The mixer may be configured to generate a modulated cover sequence by modulating a radio frequency (RF) carrier with the cover sequence. Some embodiments also include a modulator that is communicatively coupled to the mixer. The modulator may be configured to receive and modulate an altered version of the first signal and an altered version of the second signal. The modulator may additionally receive the modulated cover sequence as an RF carrier input and generate an RF output by modulating the modulated cover sequence with the altered version of the first signal and the altered version of the second signal.

Abstract: A multi-channel imaging device is provided. The multi-channel imaging device comprises a focal plane array comprising an array of pixels configured to detect radiation in a predetermined wavelength band. Subsets of the array of pixels are arranged to define a plurality of unit cell image areas. The multi-channel imaging device also comprises a lens array comprising a plurality of lens elements configured to image a scene onto the plurality of unit cell image areas. The lens elements and the unit cell image areas define a plurality of unit cells comprising at least one lens element and at least one unit cell image area. Each of the plurality of unit cells is configured to create a complete image of the scene. Additionally, a plurality of unit cell filters corresponding to the plurality of unit cells is configured to filter radiation such that each unit cell is dedicated to an image channel is also provided.

Abstract: A method of fabricating a frontside-illuminated inverted quantum well infrared photodetector may include providing a quantum well wafer having a bulk substrate layer and a quantum material layer, wherein the quantum material layer includes a plurality of alternating quantum well layers and barrier layers epitaxially grown on the bulk substrate layer. The method further includes applying at least one frontside common electrical contact to a frontside of the quantum well wafer, bonding a transparent substrate to the frontside of the quantum well wafer, thinning the bulk substrate layer of the quantum well wafer, and etching the quantum material layer to form quantum well facets that define at least one pyramidal quantum well stack. A backside electrical contact may be applied to the pyramidal quantum well stack. In one embodiment, a plurality of quantum well stacks is bonded to a read-out integrated circuit of a focal plane array.

Abstract: A method of fabricating a frontside-illuminated inverted quantum well infrared photodetector may include providing a quantum well wafer having a bulk substrate layer and a quantum material layer, wherein the quantum material layer includes a plurality of alternating quantum well layers and barrier layers epitaxially grown on the bulk substrate layer. The method further includes applying at least one frontside common electrical contact to a frontside of the quantum well wafer, bonding a transparent substrate to the frontside of the quantum well wafer, thinning the bulk substrate layer of the quantum well wafer, and etching the quantum material layer to form quantum well facets that define at least one pyramidal quantum well stack. A backside electrical contact may be applied to the pyramidal quantum well stack. In one embodiment, a plurality of quantum well stacks is bonded to a read-out integrated circuit of a focal plane array.

Abstract: A multi-channel imaging device is provided. The multi-channel imaging device includes a focal plane array having an array of pixels configured to detect radiation in a predetermined wavelength band. Subsets of the array of pixels are arranged to define a plurality of unit cell image areas. The multi-channel imaging device also includes a lens array having a plurality of lens elements configured to image a scene onto the plurality of unit cell image areas. The lens elements and the unit cell image areas define a plurality of unit cells having at least one lens element and at least one unit cell image area. Each of the plurality of unit cells is configured to create a complete image of the scene. Additionally, a plurality of unit cell filters corresponding to the plurality of unit cells is configured to filter radiation such that each unit cell is dedicated to an image channel is also provided.

Abstract: A method of fabricating a frontside-illuminated inverted quantum well infrared photodetector may include providing a quantum well wafer having a bulk substrate layer and a quantum material layer, wherein the quantum material layer includes a plurality of alternating quantum well layers and barrier layers epitaxially grown on the bulk substrate layer. The method further includes applying at least one frontside common electrical contact to a frontside of the quantum well wafer, bonding a transparent substrate to the frontside of the quantum well wafer, thinning the bulk substrate layer of the quantum well wafer, and etching the quantum material layer to form quantum well facets that define at least one pyramidal quantum well stack. A backside electrical contact may be applied to the pyramidal quantum well stack. In one embodiment, a plurality of quantum well stacks is bonded to a read-out integrated circuit of a focal plane array.

Abstract: According to one embodiment, an infrared focal plane comprises an array of pixels configured to detect optical radiation in a predetermined radiation band are positioned on a support substrate. The pixels are connected to pixel contacts on a read-out integrated circuit via pixel interconnects comprising bonding bumps. According to some embodiments, indium migration is blocked by a patterned electrical insulator comprising a plurality of intersecting walls defining a plurality of cells that surround each pixel interconnect. The patterned electrical insulator may be dimensioned such that it does not physically contact the support substrate, the array of pixels or pixel interconnects. In this manner, pixel-pair defects due to indium migration resulting from cryogenic thermal-cycling may be prevented, thereby extending the thermal-cycling lifetime of the focal plane array.

Abstract: A multi-channel imaging device is provided. The multi-channel imaging device includes a focal plane array having an array of pixels configured to detect radiation in a predetermined wavelength band. Subsets of the array of pixels are arranged to define a plurality of unit cell image areas. The multi-channel imaging device also includes a lens array having a plurality of lens elements configured to image a scene onto the plurality of unit cell image areas. The lens elements and the unit cell image areas define a plurality of unit cells having at least one lens element and at least one unit cell image area. Each of the plurality of unit cells is configured to create a complete image of the scene. Additionally, a plurality of unit cell filters corresponding to the plurality of unit cells is configured to filter radiation such that each unit cell is dedicated to an image channel is also provided.

Abstract: Particular embodiments relate generally to infrared focal plane arrays and methods thereof. According to one embodiment, an infrared focal plane comprises an array of pixels configured to detect optical radiation in a predetermined radiation band are positioned on a support substrate. The pixels are connected to pixel contacts on a read-out integrated circuit via pixel interconnects comprising bonding bumps. According to some embodiments, indium migration is blocked by a patterned electrical insulator comprising a plurality of intersecting walls defining a plurality of cells that surround each pixel interconnect. The patterned electrical insulator may be dimensioned such that it does not physically contact the support substrate, the array of pixels or pixel interconnects. In this manner, pixel-pair defects due to indium migration resulting from cryogenic thermal-cycling may be prevented, thereby extending the thermal-cycling lifetime of the focal plane array.

Abstract: Methods and systems for detection of. One method includes receiving light of a predetermined wavelength range from a source, and splitting the received light into multiple components having differing wavelengths. The method further includes directing the components toward individual locations spaced from one another. In addition, this illustrative method includes detecting at least some of the components at the locations. One illustrative system includes a plurality of detectors provided along an image facing plane of an array, wherein each detector has a width less than or equal to that of its conesponding pixel location, wherein at least two detectors are located within a single pixel location, wherein the size of each pixel location is approximately equal to the blur spot or smallest visible spot for the focal plane array, and a plurality of light pipe regions, wherein at least two light pipe regions are located within a single pixel location.

Abstract: An apparatus for selectively limiting undesired radiation from a scene which, in one embodiment, includes an optic that is operative to attenuate radiation by selectively losing transparency in response to radiation within a first wavelength band from a source. The loss of transparency affects the passage through the optic of radiation within a second wavelength band from that source. The optic can be positioned between a sensor and the scene such that the sensor is configured to receive radiation from the scene through the optic. In one embodiment, an optical limiter includes a plurality of such optics, wherein the optical limiter is configured to facilitate transmission of light corresponding to a scene, and wherein each optic is configured to receive a respective portion of the light corresponding to a respective portion of the scene. A light detector assembly and a method of limiting light energy are also included.

Abstract: A modulation/demodulation system and method comprising transmitting structure having first and second PN generators which produce distinct, synchronized, first and second PN sequences. A tapped delay line generates a plurality of symbols from the second PN sequence, each symbol corresponding to an offset of the second PN sequence by one or more chips from the epoch of the first PN sequence. A plurality of output taps are associated with the tapped delay line, with each tap corresponding to one of the symbols. A symbol selection device associated with the output taps selects from amongst the symbols based upon one or more message signal bits. The selected symbols and first PN sequence are applied to separate channels of a modulator to modulate a carrier signal. At a destination, first and second local PN generators generate first and second PN sequences which correspond to the first and second PN sequences in the transmitting structure.

Abstract: A system and method for transmitting one or more range safety commands to a launch vehicle which includes transmitting structure having a pilot code generator and at least one additional code generator for generating at least one transmitter command code corresponding to a range safety command. A PN clock continuously locks the one or more transmitter command codes with the transmitter pilot code. Sequence selection structure selectively applies the one or more transmitter command codes to a modulator which combines the transmitter pilot code and the applied transmitter command codes with a carrier signal, and transmits the pilot and command codes through a relay satellite to the vehicle. Receiving structure in the vehicle recovers the pilot and command codes, and aligns a locally generated pilot code with the recovered pilot code.

Abstract: A receiver is synchronized to a signal and the presence of data in the signal is detected by responding to the signal to derive indications of the amount of time shift necessary to achieve synchronization between the receiver and signal. The receiver is adjusted to be in synchronization with the signal in response to the time shift indications. A measure of the spread of values of the time shift indications is derived. The presence of data in the signal is flagged in response to the spread of values being less than a threshold value.

Abstract: Each diode of an indium antimonide electro-optical detector array on a dielectric backing transparent to optical energy to be detected includes a junction that less than about a half micron from the diode surface on which the energy is initially incident. The optical energy is incident on a P-type doped region prior to being incident on a bulk N-type doped region. Both P-and N-type doped regions of adjacent diodes are spaced from each other. Metal electrically connects the P-type doped regions together without interfering substantially with the incident optical energy. A multiplexer integrated circuit substrate extends parallel to the backing and includes an array of elements for selective readout of the electric property of the diodes. The elements and diodes have approximately the same topographical arrangement so that corresponding ones of the elements and diodes are aligned. An array of indium columns or bumps connects the corresponding aligned elements and diodes.

Abstract: A unit having differing thermal emissivities at differing regions thereof is monitored with an infrared camera for deriving a signal having magnitudes representing infrared emission from multiple pixels in the camera field of view. A computer responsive to the signal (a) stores data representing emissivity and standard temperature of the unit at each of the pixels, (b) combines indications of the infrared emission from each pixel and the stored data representing emissivity of each pixel to derive an indication of monitored temperature of each pixel, (c) compares the stored data representing standard temperature of each pixel and the indications of monitored temperature of each pixel, and (d) derives an indication of the deviation between the magnitude of the standard temperature and monitored temperature at each pixel. In response to the indication of the deviation at each pixel, a property of the unit related to the deviations at the pixels is derived.

Abstract: Each diode of an indium antimonide electro-optical detector array on a dielectric backing transparent to optical energy to be detected includes a junction that less than about a half micron from the diode surface on which the energy is initially incident. The optical energy is incident on a P-type doped region prior to being incident on a bulk N-type doped region. Both P- and N-type doped regions of adjacent diodes are spaced from each other. Metal electrically connects the P-type doped regions together without interfering substantially with the incident optical energy. A multiplexer integrated circuit substrate extends parallel to the backing and includes an array of elements for selective readout of the electric property of the diodes. The elements and diodes have approximately the same topographical arrangement so that corresponding ones of the elements and diodes are aligned. An array of indium columns or bumps connects the corresponding aligned elements and diodes.