Abstract: Systems and methods are provided for determining localization information for sources of seismic energy positioned below a ground surface. In accord with one series of embodiments, a method of determining localization information receives data from first seismic sensors in a first three dimensional array containing sensors emplaced below the ground surface and coherently processes the signals to provide three dimensional localization information that enables determination of an angle of arrival for a signal of interest. In combination with data from second seismic sensors in a second three dimensional array the method provides determination of a position in three dimensional space.

Abstract: An apparatus includes a light source to provide a plurality of input optical modes in a squeezed state. The apparatus also includes a network of interconnected reconfigurable beam splitters (RBSs) configured to perform a unitary transformation of the plurality of input optical modes to generate a plurality of output optical modes. An array of photon counting detectors is in optical communication with the network of interconnected RBSs and configured to measure the number of photons in each mode of the plurality of the output optical modes after the unitary transformation. The apparatus also includes a controller operatively coupled to the light source and the network of interconnected RBSs. The controller is configured to control at least one of the squeezing factor of the squeezed state of light, the angle of the unitary transformation, or the phase of the unitary transformation.

Abstract: A device for generating and controlling a magnetic field strength and a method for generating and controlling a magnetic field strength are disclosed. The generation is very stable and precise. Preferably, reference values of physical variable can be generated relatively simply and economically. In addition, magnetic flux densities can be measured with high resolution and, in particular, highly robustly. The device and the method can also be used for transmitting information, in particular for ultra-wide band communication. The required devices can be very small, in particular miniature, and mobile.

Abstract: A method for forming a sensing system responsive to a wavefield of acoustic or seismic signals. One embodiment includes providing a foil layer having first and second opposing surfaces and piezoelectric properties. The foil layer, configured as a sheet, is positioned about a frame surface which provides the foil layer a stable shape while permitting the sheet configuration of the foil layer to be responsive to a wavefield of seismic or acoustic energy. Coupling between the foil layer and the frame is so limited as to render direct coupling of the foil layer with signals of the wavefield the predominant means for stimulating the sensor element with seismic energy.

Abstract: A method includes sending a probe beam into a beam path that induces a lateral displacement to the probe beam. The probe beam includes a plurality of orthogonal spatial modes that are entangled with each other. The method also includes measuring a phase of each spatial mode from the plurality of orthogonal spatial modes in the probe beam at a detector disposed within a near field propagation regime of the probe beam. The method also includes estimating the lateral displacement of the probe beam based on a phase of each spatial mode from the plurality of spatial modes in the probe beam after the beam path.

Abstract: This invention provides for means to create a long duration high magnetic field pulse. In addition, this invention provides means for repetitive non-destructive recycling to produce a series of high magnetic field pulses. The duty cycle is the duration of high magnetic field divided by period of cycling. One objective of this invention is to increase the duty cycle, another objective of this invention is to increase the peak magnetic field.

Abstract: A method includes training a first QNN by sending a first dataset into the first QNN to generate a first output and configuring the first QNN into a first setting based on the training. The method also includes receiving a second dataset, using at least a portion of the first QNN to generate a second output using the first setting, and sending the second output to a second QNN, operatively coupled to the first QNN, to train the second QNN. The second QNN is configured in a fixed setting during training of the first QNN.

Abstract: A photonic device comprises a plurality of resonators and a plurality of optical channels. Each resonator from the plurality of resonators has a set of resonance frequencies independently selected from a set of resonance frequencies of each remaining resonator from the plurality of resonators. Each resonator from the plurality of resonators lacks substantially any linear coupling between each remaining resonator from the plurality of resonators. The plurality of resonators defines a spatial overlap region between at least two resonators from the plurality of resonators such that nonlinear optical processes are substantially optimized during operation. A plurality of optical channels is operatively coupled to the plurality of resonators. The plurality of optical channels is configured to receive light from the plurality resonators and configured to send light into the plurality of resonators.

Abstract: A method includes configuring a first plurality of beamsplitters in a network of interconnected beamsplitters of an optical circuit into a transmissive state. The optical circuit is configured to perform a linear transformation of N input optical modes, where N is a positive integer. The first plurality of beamsplitters is located along a beam path within the optical circuit and traversing a target location. The method also includes configuring a second plurality of beamsplitters in the network of interconnected beamsplitters of the optical circuit into a reflective state to reconfigure the optical circuit into a reconfigured optical circuit. The reconfigured optical circuit is configured to perform a linear transformation on M input optical modes, where M is a positive integer less than N. The second plurality of beamsplitters is located along at least one edge of the optical circuit.

Abstract: A quantum communication system for encrypting communication includes a processor configured to receive an encryption request from a mobile device. The mobile device determines a first encryption key from the mobile device. A quantum random number generator generates a second encryption key using quantum mechanics. The processor transmits the second encryption key to the mobile device. The mobile device implements a digital XOR logic gate configured to perform an XOR operation on the first encryption key and the second encryption key to generate a third encryption key.

Abstract: A photonic device comprises a plurality of resonators and a plurality of optical channels. Each resonator from the plurality of resonators has a set of resonance frequencies independently selected from a set of resonance frequencies of each remaining resonator from the plurality of resonators. Each resonator from the plurality of resonators lacks substantially any linear coupling between each remaining resonator from the plurality of resonators. The plurality of resonators defines a spatial overlap region between at least two resonators from the plurality of resonators such that nonlinear optical processes are substantially optimized during operation. A plurality of optical channels is operatively coupled to the plurality of resonators. The plurality of optical channels is configured to receive light from the plurality resonators and configured to send light into the plurality of resonators.

Abstract: A method includes sending a probe beam into a beam path that induces a lateral displacement to the probe beam. The probe beam includes a plurality of orthogonal spatial modes that are entangled with each other. The method also includes measuring a phase of each spatial mode from the plurality of orthogonal spatial modes in the probe beam at a detector disposed within a near field propagation regime of the probe beam. The method also includes estimating the lateral displacement of the probe beam based on a phase of each spatial mode from the plurality of spatial modes in the probe beam after the beam path.

Abstract: An apparatus for producing squeezed light includes a substrate and a first beam splitter integrated onto the substrate. The apparatus also includes a Mach-Zehnder interferometer integrated onto the substrate. The Mach-Zehnder interferometer has a first input coupled to a first output of the first beam splitter and a first output coupled to a second output of the first beam splitter. The apparatus also includes a waveguide integrated onto the substrate and connecting a second input of the Mach-Zehnder interferometer to a second output of the Mach-Zehnder interferometer. The waveguide and the Mach-Zehnder interferometer form a ring resonator. The ring resonator can also be replaced by a waveguide section, including, for example, a spiral waveguide.

Abstract: An apparatus includes an optical medium characterized by a third-order nonlinear optical susceptibility. The apparatus also includes a pump light source in optical communication with the optical medium and configured to send a pump light beam to the optical medium. The pump light beam includes a pulsed light beam. The apparatus also includes a drive light source in optical communication with the optical medium and configured to send a drive light beam to the optical medium. The drive light beam includes a continuous wave (CW) light beam. The pump light beam and the drive light beam are configured to generate a signal light beam in a squeezed state of light via spontaneous four-wave mixing in the optical medium.

Abstract: Quantum key distribution device includes a transmitter, including a light source, a first polarization controller, a phase modulator and an optical attenuator, all connected in series using a first optical fiber; a receiver, including a second polarization controller, a second phase modulator, a third polarization controller, a beamsplitter, and two single photon detectors, all connected in series using a second optical fiber; and a communication channel providing a light path from the transmitter to the receiver. The first and/or second optical fiber is a polarization maintaining fiber. The first and second phase modulators are actively controlled Pockels cell crystals, lithium niobate crystals or gallium arsenide crystals. The polarization controllers include a piezo-driven fiber compression device, a Pockels cell controller, a piezo-driven fiber twist device, or a non-linear optical crystal. The first and third polarization controllers use a ?/2 plate, or 45° fiber splice polarizer.

Abstract: Methods or systems for identifying seismic or acoustic signals of interest originating with moving motorized vehicles or footstep movement or stationary or moving machinery. A related system for monitoring an area includes a plurality of sensing devices each comprising a frame and a piezo-electric sensor element. A monitoring device is coupled to receive information from each of the sensing devices. One method includes providing a processing chain coupled to receive signal data from a sensor device which receives the signals, including a detection stage, a Joint Time Frequency (JTF) domain stage, and a classification stage. The detection stage identifies presence of signals that emerge from the background. The JTF domain stage estimates the state of the signals of interest over time. The classification stage assesses the previously derived information to form a decision about source identity. In one embodiment, the detector stage performs detections on a single cycle basis.

Abstract: A sensing system responsive to a wavefield of acoustic or seismic signals. In one embodiment, the system includes a frame having a surface of tubular shape about which a layer of piezoelectric material can be positioned to extend along a first direction. A piezoelectric element is positioned under tension to apply a force against the frame, which tension increases signal response of the element.

Abstract: The invention relates to quantum cryptography, and includes a communication system for transmitting a cryptographic key between the ends of a channel, including a transmitting node (Alice) comprising a beam splitter, an electro-optical attenuator, an amplitude modulator, a phase modulator, a storage line, a Faraday mirror, a synchronization detector; a receiving node (Bob) that includes avalanche photodiodes, a beam splitter, a circulator, a delay line, a phase modulator, a polarizing beam splitter, a Mach-Zehnder interferometer, and also a quantum channel for connecting these nodes. In this case, for the storage line is placed between the electro-optical phase modulator of the sender and the Faraday mirror. The limiting frequency of the laser pulse repetition at a fixed value of their width is increased, which makes it possible to use an autocompensation circuit at a frequency corresponding to the width of the laser pulse, which is the maximum possible result.

Abstract: Methods or systems for identifying seismic or acoustic signals of interest originating with moving motorized vehicles or footstep movement or stationary or moving machinery. A related system for monitoring an area includes a plurality of sensing devices each comprising a frame and a piezo-electric sensor element. A monitoring device is coupled to receive information from each of the sensing devices. One method includes providing a processing chain coupled to receive signal data from a sensor device which receives the signals, including a detection stage, a Joint Time Frequency (JTF) domain stage, and a classification stage. The detection stage identifies presence of signals that emerge from the background. The JTF domain stage estimates the state of the signals of interest over time. The classification stage assesses the previously derived information to form a decision about source identity. In one embodiment, the detector stage performs detections on a single cycle basis.

Abstract: A method for forming a sensing system responsive to a wavefield of acoustic or seismic signals. One embodiment includes providing a foil layer having first and second opposing surfaces and piezoelectric properties. The foil layer, configured as a sheet, is positioned about a frame surface which provides the foil layer a stable shape while permitting the sheet configuration of the foil layer to be responsive to a wavefield of seismic or acoustic energy. Coupling between the foil layer and the frame is so limited as to render direct coupling of the foil layer with signals of the wavefield the predominant means for stimulating the sensor element with seismic energy.