Abstract: A method for performing an operation on an input signal includes receiving, by a multi-mode waveguide, the input signal imposed on laser light. The received input signal imposed on the laser light is propagated through the waveguide a plurality of times in a plurality of modes, the modes interfering each time they propagate through the waveguide to generate an interference pattern of the plurality of modes. Portions of the interference pattern of the plurality of modes are nonlinearly activated each time those modes propagate through the multi-mode waveguide. Portions of the activated interference pattern of the plurality of modes are output to an optical detector array in parallel with one another each time those modes propagate through the multi-mode waveguide.

Abstract: A method for performing an operation on an input signal includes receiving, by a multi-mode waveguide, the input signal imposed on laser light. The received input signal imposed on the laser light is propagated through the waveguide a plurality of times in a plurality of modes, the modes interfering each time they propagate through the waveguide to generate an interference pattern of the plurality of modes. Portions of the interference pattern of the plurality of modes are nonlinearly activated each time those modes propagate through the multi-mode waveguide. Portions of the activated interference pattern of the plurality of modes are output to an optical detector array in parallel with one another each time those modes propagate through the multi-mode waveguide.

Abstract: An apparatus that includes a phased array configured to monitor a broad bandwidth with low rate ADC achieving sub-Nyquist rate sampling with 100 percent duty cycle. The phased array includes a plurality of phased array elements. Each of the phased array elements are inserted with a non-uniform true time delay to enable simultaneous measurement of an AOA and a frequency of an incident RF signal.

Abstract: Under one aspect, a method for performing an operation is provided. The method can include receiving, by different physical locations of a multi-mode waveguide, an input signal and a plurality of coefficients imposed on laser light. The method also can include generating, by the multi-mode waveguide, a speckle pattern based on the different physical locations, the input signal, and the plurality of coefficients. The method also can include adjusting at least one of the coefficients based on the speckle pattern.

Abstract: Under one aspect, a method for performing an operation is provided. The method can include receiving, by different physical locations of a multi-mode waveguide, an input signal and a plurality of coefficients imposed on laser light. The method also can include generating, by the multi-mode waveguide, a speckle pattern based on the different physical locations, the input signal, and the plurality of coefficients. The method also can include adjusting at least one of the coefficients based on the speckle pattern.

Abstract: An apparatus that includes a phased array configured to monitor a broad bandwidth with low rate ADC achieving sub-Nyquist rate sampling with 100 percent duty cycle. The phased array includes a plurality of phased array elements. Each of the phased array elements are inserted with a non-uniform true time delay to enable simultaneous measurement of an AOA and a frequency of an incident RF signal.

Abstract: A method for measuring reactive hyperemia in a subject is disclosed. The method includes performing a first segmental cuff plethysmography to generate a baseline arterial compliance curve and/or a baseline pressure-area (P-A) curve, performing a second segmental cuff plethysmography to generate a hyperemic arterial compliance curve and/or a hyperemic P-A curve, and calculating an area between the baseline and the hyperemic curves. The size of the area can be used as an indication of endothelial dysfunction (ED) and ED-related diseases.

Abstract: Under one aspect, a method for performing a linear algebra operation includes imposing matrix elements onto a chirped optical carrier; inputting into a multi-mode optic the matrix elements imposed on the chirped optical carrier; outputting by the multi-mode optic a speckle pattern based on the matrix elements imposed on the optical carrier; and performing a linear algebra operation on the matrix elements based on the speckle pattern. The matrix elements can be from matrix A and a vector b, and the multi-mode optic can optically transform each of matrix A and vector b by a speckle transformation S, so as to output a speckle pattern including elements of a matrix SA of dimension p,n and matrix elements of a vector Sb of dimension p. The linear algebra operation can include generating {tilde over (x)}=(SA)†Sb, wherein † indicates a pseudo-inverse operation.

Abstract: Under one aspect, a method for performing a linear algebra operation includes imposing matrix elements onto a chirped optical carrier; inputting into a multi-mode optic the matrix elements imposed on the chirped optical carrier; outputting by the multi-mode optic a speckle pattern based on the matrix elements imposed on the optical carrier; and performing a linear algebra operation on the matrix elements based on the speckle pattern. The matrix elements can be from matrix A and a vector b, and the multi-mode optic can optically transform each of matrix A and vector b by a speckle transformation S, so as to output a speckle pattern including elements of a matrix SA of dimension p,n and matrix elements of a vector Sb of dimension p. The linear algebra operation can include generating {tilde over (x)}=(SA)†Sb, wherein † indicates a pseudo-inverse operation.

Abstract: An improved approach to direction finding using a super delta monopulse beamformer is disclosed. A super delta channel signal that includes direction finding information from two circular delta channels is formed and output by the super delta monopulse beamformer. This super delta channel signal uses only two channels, but is able to realize the accuracy of conventional three channel systems.

Abstract: Systems and methods for converting wideband signals into the digital domain are provided herein. The system may include an electronic or guided-wave optic based replicator configured to obtain at least M replicas of a signal applied thereto, and an electronic or guided-wave optic based segmenter configured to segment a signal applied thereto into at least N segments based on time or wavelength. Together, the replicator and the segmenter obtain M×N segment replicas of the received signal. An electronic or guided-wave optic based mixer is configured to multiply the M×N segment replicas by a mixing matrix having dimension M×N and then to form M integrations each of N segment replicas so as to obtain a measurement vector of length M. A signal recovery processor is configured to obtain a digital representation of the received signal based on the measurement vector and the mixing matrix.

Abstract: Systems and methods for converting wideband signals into the digital domain are provided herein. The system may include an electronic or guided-wave optic based replicator configured to obtain at least M replicas of a signal applied thereto, and an electronic or guided-wave optic based segmenter configured to segment a signal applied thereto into at least N segments based on time or wavelength. Together, the replicator and the segmenter obtain M×N segment replicas of the received signal. An electronic or guided-wave optic based mixer is configured to multiply the M×N segment replicas by a mixing matrix having dimension M×N and then to form M integrations each of N segment replicas so as to obtain a measurement vector of length M. A signal recovery processor is configured to obtain a digital representation of the received signal based on the measurement vector and the mixing matrix.

Abstract: An improved approach to direction finding using a super delta monopulse beamformer is disclosed. A super delta channel signal that includes direction finding information from two circular delta channels is formed and output by the super delta monopulse beamformer. This super delta channel signal uses only two channels, but is able to realize the accuracy of conventional three channel systems.