Abstract: Light emitting devices with improved light extraction efficiency are provided. The light emitting devices have a stack of layers including semiconductor layers comprising an active region. The stack is bonded to a transparent optical element.

Abstract: Aspects of the invention include plasma generating devices and systems thereof, as well as methods of using the same in plasma generation. Embodiments of the plasma generating devices include a resonator having a discharge gap and a ground plane disposed on opposing sides of a substrate; and a gas flow element configured to flow gas through the discharge gap. In using the plasma generating devices, a gas is flowed through the discharge gap and sufficient power is applied to the resonator to produce a plasma, e.g., in the form of a plasma jet, at the discharge gap. The subject devices and methods find use in a variety of different applications.

Abstract: Aspects of the invention include plasma generating devices having alternative ground geometries and systems thereof, as well as methods of using the same in plasma generation. The plasma generating devices of the invention include a resonator with a discharge gap disposed on a substrate and a ground element. Embodiments of the ground element of the plasma generating devices of the invention include those that are internal, external, coplanar or a combination thereof. The subject plasma generating devices, systems and methods find use in a variety of different applications.

Abstract: A microwave imaging system for performing standoff microwave imaging includes an antenna array with a plurality of antenna elements, each capable of being programmed with a respective direction coefficient to direct microwave illumination toward a target within a volume that includes a standoff region, and each capable of being programmed with a respective additional direction coefficient to receive reflected microwave illumination reflected from the target. A processor measures an intensity of the reflected microwave illumination to determine a value of a voxel within a microwave image of the volume. The processor constructs the microwave image with a resolution sufficient to identify objects within the standoff region.

Abstract: A handheld microwave imaging device provides screening of objects, such as persons and other items. The imaging device includes an antenna array of antenna elements, each capable of being programmed with a respective direction coefficient to direct microwave illumination toward a target associated with the object, and each capable of being programmed with a respective additional direction coefficient to receive reflected microwave illumination reflected from the target. The imaging device further includes a processor operable to measure an intensity of the reflected microwave illumination to determine a value of a voxel within a microwave image of the object. The antenna array is compliantly mounted in a first portion of a support structure, while a second portion of the support structure defines a handle for enabling a user to control movement of the device.

Abstract: A system and method are disclosed for calibrating non-linear behavior using attenuated stimuli and responses which allows for calibration with unknown stimulus and less expensive sources and receivers. The device under test is stimulated with a signal and then an attenuated version of the same signal, so that non-linear differences between responses can be attributed to the device rather than the signal source. Alternatively, or in conjunction with attenuation of the stimulus, the output of the device at different response amplitudes can be selectively attenuated such that the receiver measures approximately the same amplitude. This allows non-linear differences between measurements to be attributed to the device rather than the receiver. Two or more different signal sources can also be used, where responses are measured for each signal individually and then for at least one linear combination of signals.

Abstract: A nanoscale displacement detector includes a cantilever integrated with an optical resonator, referred to herein as a “microresonator.” The microresonator and cantilever are configured such that displacement of the cantilever relative to the microresonator causes a change in the resonant frequency of the microresonator. The change in the resonant frequency of the microresonator is used to monitor cantilever displacement. In an embodiment, the microresonator includes a cavity that faces the cantilever and the cantilever includes a protrusion that faces the microresonator and is aligned with the cavity.

Abstract: A microwave imaging system suppresses sidelobes in a microwave image captured using a sparse antenna array using an illumination system that operates in two different illumination modes. The antenna array including subarrays of antenna elements arranged in a sparse geometry to form complementary subarray patterns. The illumination system operates in a first mode to transmit microwave illumination to both of the complementary subarray patterns of the antenna array and receive reflected microwave illumination from both of the complementary subarray patterns of the antenna array to produce a first receive signal. The illumination system further operates in a second mode to transmit microwave illumination to a first one of the complementary subarray patterns of the antenna array and receive reflected microwave illumination from a second one of the complementary subarray patterns of the antenna array to produce a second receive signal.

Abstract: An antenna array for use within a microwave imaging system to capture a microwave image of a target is selectively programmed to optimize one or more parameters of the microwave imaging system. The array includes a plurality of antenna elements, each capable of being programmable with a respective phase shift to direct a beam of microwave radiation toward the target such that the microwave radiation from each of the plurality of antenna elements arrives at the target substantially in-phase. To optimize a parameter of the microwave imaging system, the phase shifts of selective ones of the antenna elements are altered, while still maintaining the substantially in-phase microwave radiation at the target.

Abstract: A scanning panel for use in a microwave imaging system captures a microwave image of a target using two complementary arrays of antenna elements. Each of the antenna elements in a first array is capable of being programmed with a respective phase delay to direct a transmit beam of microwave illumination toward the target in a transmit beam pattern, and each of the antenna elements in a second array is capable of receiving reflected microwave illumination reflected from the target in a receive beam in a receive beam pattern complementary to the transmit beam pattern. The microwave image of the target is formed at an intersection between the transmit beam and the receive beam.

Abstract: A microwave imaging system captures a microwave image of a target and minimizes noise in the microwave image using phase differentiation. A reflector antenna array is provided including a plurality of antenna elements for reflecting microwave radiation towards the target and for reflecting microwave radiation reflected from the target towards a microwave receiver. A processor programs the antenna elements with respective first phase shifts to capture a first microwave image of the target, and programs the antenna elements with respective second phase shifts to capture a second microwave image of the target. The first phase shift of each antenna element is 180 degrees different than the second phase shift for that antenna element. The processor minimizes noise from a combination of the first microwave image and the second microwave image.

Abstract: An antenna array for use within a microwave imaging system includes a plurality of reflecting antenna elements, each capable of being programmed with respective phase-shifts in a first pattern to direct a first beam of microwave radiation towards a first target, and each being capable of being programmed with respective phase-shifts in a second pattern to direct a second beam of microwave radiation towards a second target. To capture a microwave image of an object, the antenna elements are programmed with respective phase-shifts in an interleaved pattern including a portion of the first pattern and a portion of the second pattern.

Abstract: An inspection system uses microwave radiation to capture a microwave image of a transportable item. The system includes a transmit scanning panel including a transmit array of transmit antenna elements, each being programmable with a respective phase delay to direct a transmit beam of microwave radiation toward a target of the transportable item for transmission of the microwave radiation through the target. The system further includes a receive scanning panel including a receive array of receive antenna elements, each being programmable with a respective phase delay to receive a receive beam of microwave radiation from the target. A processor measures the amplitude and phase of the microwave radiation in the receive beam to determine a relative value of a pixel within the microwave image of the transportable item based on a reference value of the pixel.

Abstract: A microwave imaging system uses microwave radiation provided by a microwave source to image targets. The system includes an array of antenna elements that are capable of being programmed with a respective transmission coefficient to direct the microwave illumination from the microwave source toward a position on the target. The antenna elements are further capable of being programmed with a respective additional transmission coefficient to receive reflected microwave illumination reflected from the position on the target and direct the reflected microwave illumination towards a microwave receiver. A processor is operable to measure an intensity of the reflected microwave illumination to determine a value of a pixel within an image of the target. Multiple beams can be directed towards the target to obtain corresponding pixel values for use by the processor in constructing the image.

Abstract: A microwave imaging system uses microwave radiation provided by a microwave source to image targets. The system includes an array of antenna elements that are capable of being programmed with a respective direction coefficient to direct the microwave illumination from the microwave source toward a position on the target. The antenna elements are further capable of being programmed to receive reflected microwave illumination reflected from the position on the target. A processor is operable to measure an intensity of the reflected microwave illumination to determine a value of a pixel within an image of the target. Multiple beams can be directed towards the target to obtain corresponding pixel values for use by the processor in constructing the image.

Abstract: A reflectarray utilizes switching devices with non-ideal impedance characteristics to vary the impedance of reflecting elements. The antennas of the reflecting elements are configured as a function of the impedance of the non-ideal switching devices to provide optimal phase-amplitude performance. In particular, the antennas are configured such that the impedance of each antenna is proportional to the square root of the impedance of the non-ideal switching devices when in an on state and when in an off state.

Abstract: A technique for imaging an object with a coherent beam of electromagnetic radiation involves sequencing at least a portion of the coherent beam through a set of orthogonal transverse spatial modes and summing the output signals that result from set of orthogonal transverse spatial modes. To create an image of an object, the coherent beam is applied to multiple spots on the object and~sequenced through the same set of orthogonal transverse spatial modes at each spot. The output signals generated from the sequencing are summed on a per-spot basis.

Abstract: An imaging system includes an optical (visible-light or near IR) imaging system and a microwave imaging system. The optical imaging system captures an optical image of the object, produces optical image data representing the optical image and extracts optical image information from the optical image data. The microwave imaging system produces microwave image data representing a microwave image of the object in response to the optical image information.

Abstract: An imaging system includes an optical (visible-light or near IR) imaging system and a microwave imaging system. The optical imaging system captures an optical image of the object, produces optical image data representing the optical image and extracts optical image information from the optical image data. The microwave imaging system produces microwave image data representing a microwave image of the object in response to the optical image information.

Abstract: A security inspection system uses microwave radiation to image targets on a human subject or other item. The system includes an array of antenna elements that are programmable with a respective phase delay to direct a beam of microwave illumination toward a target on the human subject or item. The antenna elements are further capable of receiving reflected microwave illumination reflected from the target. A processor is operable to measure an intensity of the reflected microwave illumination to determine a value of a pixel within an image of the human subject or item. Multiple beams can be directed towards the human subject or item to obtain corresponding pixel values for use by the processor in constructing the image.