Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, that validate the synchronization of controllers in an aquaculture environment. One of the methods includes an image processor that receives images generated by a first image generating device that includes a light filter that is associated with light of a particular light frequency while an aquaculture environment was illuminated with light. Based on the image that was generated by the first image generating device, the image processor determines whether the intensity value of the light frequency in the image satisfies a threshold value. Based on determining whether the intensity value of the light frequency in the image satisfies the threshold value, the image processor determines whether the aquaculture environment was illuminated with light of the particular light frequency when the image was generated.

Abstract: Methods, systems, and computer-readable media that implement an autonomous modular breakwater system. An example system includes a plurality of autonomous submersible structures, each configured to mechanically link to any other of the plurality of autonomous submersible structures to form a breakwater.

Abstract: A multi-channel photonic demultiplexer includes an input region to receive a multi-channel optical signal including four distinct wavelength channels, four output regions, each adapted to receive a corresponding one of the four distinct wavelength channels demultiplexed from the multi-channel optical signal, and a dispersive region optically disposed between the input region and the four output regions. The dispersive region includes a first material and a second material inhomogeneously interspersed to form a plurality of interfaces that each correspond to a change in refractive index of the dispersive region and collectively structure the dispersive region to optically separate each of the four distinct wavelength channels from the multi-channel optical signal and respectively guide each of the four distinct wavelength channels to the corresponding one of the four output regions.

Abstract: The technology employs a state-based power control loop (PCL) architecture to maintain tracking and communication signal-to-noise ratios at suitable levels for optimal tracking performance and data throughput in a free-space optical communication system. Power for a link is adjustable to stay within a functional range of receiving sensors in order to provide continuous service to users. This avoids oversaturation and possible damage to the equipment. The approach can include decreasing or increasing the power to counteract a surge or drop while maintaining a near constant received power at a remote communication device. The system may receive power adjustment feedback from another communication terminal and perform state-based power control according to the received feedback. This can include re-initializing and reacquiring a link with the other communication terminal automatically after loss of power, without human intervention.

Abstract: Techniques for simulating networks using dynamics-based constraints are disclosed.

Abstract: A system for reducing plasma instability is disclosed. The system includes: an outer electrode having a first end and a second end spaced from the first end; and an inner electrode disposed inside of a void defined within the outer electrode and arranged coaxial with the outer electrode. The inner electrode includes: a base end defined by the first end of the outer electrode; and an apical end spaced from the base end. The system includes a fiber injector configured to inject a frozen fiber into the void from the apical end of the inner electrode; an electrode power source configured to energize the outer electrode and the inner electrode, and thereby, cause a plasma contained within the outer electrode to flow axially along the frozen fiber; and a frozen fiber power source configured to drive an electrical pulse to the frozen fiber.

Abstract: Methods for designing a mode-selective optical device including one or more optical interfaces defining an optical cavity include: defining a loss function within a simulation space encompassing the optical device, the loss function corresponding to an electromagnetic field having an operative wavelength within the optical device resulting from an interaction between an input electromagnetic field at the operative wavelength and the one or more optical interfaces of the optical device; defining an initial structure for each of the one or more optical interfaces, each initial structure being defined using a plurality of voxels; determining values for at least one structural parameter and/or at least one functional parameter of the one or more optical interfaces by solving Maxwell's equations; and defining a final structure of the one or more optical interfaces based on the values for the one or more structural and/or functional parameters.

Abstract: A system includes a transmitter configured to output an optical signal. The transmitter includes a seed laser, an optical array including a plurality of array elements, and a plurality of phase shifters in a multi-layer arrangement. The multi-layer arrangement includes a plurality of layers between the seed laser and the optical array, wherein a first layer of the plurality of layers transmits light to a second layer of the plurality of layers. The first layer has fewer phase shifters than the second layer. The multi-layer arrangement also includes a plurality of branches wherein each branch includes a phase shifter from each of the plurality of layers connected in series between the seed laser and one of the plurality of array elements. Each phase shifter is configured to shift the optical signal incrementally to amass a total phase shift for each of the plurality of array elements.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for simulating a concrete mixture. One of the methods includes obtaining an optical characterization of physical particles, generating a multispherical approximation of the physical particles, the multispherical approximation having reduced dimensionality compared to the optical characterization, simulating an aggregate mixture by applying the multispherical approximation of the particles to a physics simulator to obtain a predicted performance of the proposed aggregate mixture, selectively altering the aggregate mixture based on a comparison with performance metrics and simulating the altered aggregate mixture until the predicted performance satisfies the performance metrics to obtain a final aggregate mixture, and outputting the final aggregate mixture.

Abstract: A compound motor-generator system including a first motor-generator and a second motor-generator. The first motor generator includes a stator having a set of three-phase field windings and a first rotor disposed inside and coaxial with the stator and configured to rotate relative to the stator. The second motor-generator includes a rotational stator and a second rotor coupled to a common shaft with the rotor of the first motor-generator and disposed inside and coaxial to the rotational stator. The rotational stator is configured to rotate relative to the second rotor and at a higher rotational speed than the second rotor.

Abstract: Techniques for selecting a spectroscopic light source include obtaining a light source dataset and a spectroscopic dataset, initializing a genetic algorithm, selecting a first individual solution and a second individual solution from an initial generation of solutions, generating a new individual solution from the first and second individual solutions by combining their respective chromosome encodings, evaluating a specificity of the new individual solution to a target material, adding the new individual solution to a new generation of solutions, populating the new generation of solutions with a plurality of additional individual solutions, generating one or more descendent generations of solutions by iterating the genetic algorithm, selecting one or more implementation individual solutions exhibiting a threshold specificity to the target material, and outputting the one or more implementation individual solutions.

Abstract: Techniques for selecting a spectroscopic light source include obtaining a light source dataset and a spectroscopic dataset, initializing a genetic algorithm, selecting a first individual solution and a second individual solution from an initial generation of solutions, generating a new individual solution from the first and second individual solutions by combining their respective chromosome encodings, evaluating a specificity of the new individual solution to a target material, adding the new individual solution to a new generation of solutions, populating the new generation of solutions with a plurality of additional individual solutions, generating one or more descendent generations of solutions by iterating the genetic algorithm, selecting one or more implementation individual solutions exhibiting a threshold specificity to the target material, and outputting the one or more implementation individual solutions.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for escape detection and mitigation for aquaculture. In some implementations, a method includes obtaining one or more images that depict one or more fish within a population of fish that are located within an enclosure; providing, to one or more detection models configured to classify fish that are depicted within the images as likely being member or as likely not being member of a type of fish, the one or images; generating, as a result of providing the one or more images to the one or more detection models, a value that reflects a quantity of fish that are depicted in the images that are likely a member of the type of fish; and detecting a condition based at least on the value.

Abstract: The disclosure provides for a free-space optical communication system that includes a first lens group, a field corrector lens, and a second lens group. The first lens group is configured to receive light received from a remote free-space optical transmitter. The first lens group has a first focal plane. The field corrector lens is positioned between the first lens group and the first focal plane of the first lens group and positioned closer to the first focal plane than the first lens group. The first lens group also is made of material having an index of refraction of at least 2.0, and has a second focal plane. The second lens group is positioned at the second focal plane of the field corrector lens and is configured to couple light to a sensor.

Abstract: This disclosure describes a system and method for generating images and location data of a subsurface object using existing infrastructure as a source. Many infrastructure objects (e.g., pipes, cables, conduits, wells, foundation structures) are constructed of rigid materials and have a known shape and location. Additionally these infrastructure objects can have exposed portions that are above or near the surface and readily accessible. A signal generator can be affixed to the exposed portion of the infrastructure object, which induces acoustic energy, or vibrations in the object. The object with affixed signal generator can then be used as a source in performing a subsurface imaging of subsurface objects, which are not exposed.

Abstract: Techniques for simulating networks using dynamics-based constraints are disclosed.

Abstract: A magnetometry apparatus includes an array of magnetometer pixels. Each magnetometer pixel includes an electron spin defect body including a plurality of lattice point defects, and a microwave field transmitter operable to apply a microwave field to the electron spin defect body. The apparatus may also include an optical source configured to emit input light of a first wavelength that excites the plurality of lattice point defects of the electron spin defect bodies from a ground state to an excited state, and a photodetector arranged to receive photoluminescence of a second wavelength emitted from a first electron spin defect body of a first magnetometer pixel of the array of magnetometer pixels. The second wavelength is different from the first wavelength.

Abstract: A magnetometer includes a sample signal device; a reference signal device; a microwave field generator operable to apply a microwave field to the sample signal device and the reference signal device; an optical source configured to emit light including light of a first wavelength that interacts optically with the sample signal device and with the reference signal device; at least one photodetector arranged to detect a sample photoluminescence signal including light of a second wavelength emitted from the sample signal device and a reference photoluminescence signal including light of the second wavelength emitted from the reference signal device, in which the first wavelength is different from the second wavelength; and a magnet arranged adjacent to the sample signal device and the reference signal device.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium that provides an enhanced synchronization framework. One of the methods includes a primary and a second device that receive configuration information which identifies one or more actions to be performed by the secondary device when it receives specified pulses of a sequence of pulses from the primary device. The primary device transmits a sequence of pulses. The primary and the secondary device receive a particular pulse from the sequence of pulses. The secondary device determines whether the particular pulse satisfies one or more predetermined criteria and generates an instruction based on the determination.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for using machine learning models for plant biotechnology. One of the methods includes obtaining a network input comprising an image depicting a plurality of plant cells or regions of plant tissue; processing the network input using a machine learning model to obtain an identification of one or more particular biotechnologically-modifiable plant cells or one or more particular biotechnologically-modifiable regions of the plant tissue; excising or delineating the one or more identified plant cells or the one or more identified regions of the plant tissue; and delivering exogenous material to the excised or delineated plant cells or regions of plant tissue.