Abstract: A system for optically modulating a plurality of optical channels includes a power delivery module adapted to convert a coherent light beam into a plurality of optical channels, at least one optical modulator, optically coupled to the power delivery module, the at least one optical modulator adapted to optically modulate each of the plurality of the optical channels, and a vacuum chamber having a trapping plane therein, the vacuum chamber adapted to generate an addressable array of trapped particles at the trapping plane, wherein each of the plurality of optical channels is optically coupled to at least one of the trapped particles of the addressable array.

Abstract: The exponential growth in deep learning models is challenging existing computing hardware. Optical neural networks (ONNs) accelerate machine learning tasks with potentially ultrahigh bandwidth and nearly no loss in data movement. Scaling up ONNs involves improving scalability, energy efficiency, compute density, and inline nonlinearity. However, realizing all these criteria remains an unsolved challenge. Here, we demonstrate a three-dimensional spatial time-multiplexed ONN architecture based on dense arrays of microscale vertical cavity surface emitting lasers (VCSELs). The VCSELs, coherently injection-locked to a leader laser, operate at gigahertz data rates with a 7T-phase-shift voltage on the 10-millivolt level. Optical nonlinearity is incorporated into the ONN with no added energy cost using coherent detection of optical interference between VCSELs.

Abstract: Component errors prevent linear photonic circuits from being scaled to large sizes. These errors can be compensated by programming the components in an order corresponding to nulling operations on a target matrix X through Givens rotations X?T†X, X?XT†. Nulling is implemented on hardware through measurements with feedback, in a way that builds up the target matrix even in the presence of hardware errors. This programming works with unknown errors and without internal sources or detectors in the circuit. Modifying the photonic circuit architecture can reduce the effect of errors still further, in some cases even rendering the hardware asymptotically perfect in the large-size limit. These modifications include adding a third directional coupler or crossing after each Mach-Zehnder interferometer in the circuit and a photonic implementation of the generalized FFT fractal.

Abstract: Programmable photonic circuits of reconfigurable interferometers can be used to implement arbitrary operations on optical modes, providing a flexible platform for accelerating tasks in quantum simulation, signal processing, and artificial intelligence. A major obstacle to scaling up these systems is static fabrication error, where small component errors within each device accrue to produce significant errors within the circuit computation. Mitigating errors usually involves numerical optimization dependent on real-time feedback from the circuit, which can greatly limit the scalability of the hardware. Here, we present a resource-efficient, deterministic approach to correcting circuit errors by locally correcting hardware errors within individual optical gates. We apply our approach to simulations of large-scale optical neural networks and infinite impulse response filters implemented in programmable photonics, finding that they remain resilient to component error well beyond modern day process tolerances.

Abstract: Component errors prevent linear photonic circuits from being scaled to large sizes. These errors can be compensated by programming the components in an order corresponding to nulling operations on a target matrix X through Givens rotations X?T†X, X?XT†. Nulling is implemented on hardware through measurements with feedback, in a way that builds up the target matrix even in the presence of hardware errors. This programming works with unknown errors and without internal sources or detectors in the circuit. Modifying the photonic circuit architecture can reduce the effect of errors still further, in some cases even rendering the hardware asymptotically perfect in the large-size limit. These modifications include adding a third directional coupler or crossing after each Mach-Zehnder interferometer in the circuit and a photonic implementation of the generalized FFT fractal.

Abstract: The typical approach to transfer quantum information between two superconducting quantum computers is to transduce the quantum information into the optical regime at the first superconducting quantum computer, transmit the quantum information in the optical regime to the second superconducting quantum computer, and then transduce the quantum information back into the microwave regime at the second superconducting quantum computer. However, direct microwave-to-optical and optical-to-microwave transduction have low fidelity due to the low microwave-optical coupling rates and added noise. These problems compound in consecutive microwave-to-optical and optical-to-microwave transduction steps. We break this rate-fidelity trade-off by heralding end-to-end entanglement with one detected photon and teleportation. In contrast to cascaded direct transduction, our technology absorbs the low optical-microwave coupling efficiency into the entanglement heralding step.

Abstract: A method for interacting with quantum states over respective time intervals comprises: providing, from at least one optical fiber interface, a fiber-coupled optical mode that controls optical coupling to and/or from an optical fiber, where at least a portion of the optical fiber extends outside of an interior of a housing comprising the at least one optical fiber interface; providing a quantum state from each quantum state emission element (QSEE) housed on or inside the housing; providing, from each of multiple portions of one or more directional structures, a preferential direction for an associated element-coupled optical mode that controls optical coupling to and from a different respective subset of one or more of the QSEEs; and scanning a scanning structure housed on or inside the housing to change an overlap between the fiber-coupled optical mode and a different respective one of the element-coupled optical modes over each time interval.

Abstract: Quantum information processing involves entangling large numbers of qubits, which can be realized as defect centers in a solid-state host. The qubits can be implemented as individual unit cells, each with its own control electronics, that are arrayed in a cryostat. Free-space control and pump beams address the qubit unit cells through a cryostat window. The qubit unit cells emit light in response to these control and pump beams and microwave pulses applied by the control electronics. The emitted light propagates through free space to a mode mixer, which interferes the optical modes from adjacent qubit unit cells for heralded Bell measurements. The qubit unit cells are small (e.g., 10 ?m square), so they can be tiled in arrays of up to millions, addressed by free-space optics with micron-scale spot sizes. The processing overhead for this architecture remains relatively constant, even with large numbers of qubits, enabling scalable large-scale quantum information processing.

Abstract: In-network Optical Inference (IOI) provides low-latency machine learning inference by leveraging programmable switches and optical matrix multiplication. IOI uses a transceiver module, called a Neuro Transceiver, with an optical processor to perform linear operations, such as matrix multiplication, in the optical domain. IOI's transceiver modules can be plugged into programmable packet switches, which are programmed to perform non-linear activations in the electronic domain and to respond to inference queries. Processing inference queries at the programmable packet switches inside the network, without sending them to cloud or edge inference servers, significantly reduces end-to-end inference latency experienced by users.

Abstract: The next-generation of optoelectronic systems will require efficient optical signal transfer between many discrete photonic components integrated onto a single substrate. While modern assembly processes can easily integrate thousands of electrical components onto a single board, photonic assembly is far more challenging due to the wavelength-scale alignment tolerances required. Here we address this problem by introducing a self-aligning photonic coupler insensitive to x, y, z displacement and angular misalignment. The self-aligning coupler provides a translationally invariant evanescent interaction between waveguides by intersecting them at an angle, which enables a lateral and angular alignment tolerance fundamentally larger than non-evanescent approaches such as edge coupling. This technology can function as a universal photonic connector interfacing photonic integrated circuits and microchiplets across different platforms.

Abstract: Chemical-shift nuclear magnetic resonance (NMR) spectroscopy involves measuring the effects of chemical bonds in a sample on the resonance frequencies of nuclear spins in the sample. Applying a magnetic field to the sample causes the sample nuclei to emit alternating current magnetic fields that can be detected with color centers, which can act as very sensitive magnetometers. Cryogenically cooling the sample increases the sample's polarization, which in turn enhances the NMR signal strength, making it possible to detect net nuclear spins for very small samples. Flash-heating the sample or subjecting it to a magic-angle-spinning magnetic field (instead of a static magnetic field) eliminates built-in magnetic field inhomogeneities, improving measurement sensitivity without degrading the sample polarization.

Abstract: Provided herein is a photonic integrated circuit and methods for controlling a photonic integrated circuit that can utilize the resonant frequency of one or more components of the photonic integrated circuit to enhance the response of the circuit. At least one component of the photonic integrated circuit can be driven by an electrical signal whose frequency is substantially equal to the mechanical resonance frequency of the component such that the response of the optical component is increased. The component of the photonic integrated circuit can include a phase shifter that can impart a phase shift on a received optical signal. By driving the phase shifter with an electrical signal that is equal to the mechanical resonance frequency of the optical phase shifter, less power can be required to impart a desired phase shift on a received optical signal. The optical components can be implemented using piezoelectric cantilevers.

Abstract: A spectrally multiplexed quantum repeater (SMuQR) based on spatially arrayed nodes of frequency-multiplexed multi-qubit registers uses the natural inhomogeneous distribution of optical transition frequencies in solid state defect centers. This distribution enables spectrally selective, individual addressing of large numbers of defect centers within an optical diffraction limited spot along a long cavity or waveguide. The spectral selection relies on frequency shifting an incident optical field at a rate as fast as once per defect center lifetime. The defect centers are resonant at visible frequencies and emit visible single photons which are down-converted to a wavelength compatible with long-distance transmission via conventional optical fiber. The down-converted photons are all at the same telecommunications wavelength, with the different spectral bins mapped to different temporal bins to preserve the multiplexing in the time domain, for distribution to other nodes in the quantum network.

Abstract: Quantum information processing involves entangling large numbers of qubits, which can be realized as defect centers in a solid-state host. The qubits can be implemented as individual unit cells, each with its own control electronics, that are arrayed in a cryostat. Free-space control and pump beams address the qubit unit cells through a cryostat window. The qubit unit cells emit light in response to these control and pump beams and microwave pulses applied by the control electronics. The emitted light propagates through free space to a mode mixer, which interferes the optical modes from adjacent qubit unit cells for heralded Bell measurements. The qubit unit cells are small (e.g., 10 ?m square), so they can be tiled in arrays of up to millions, addressed by free-space optics with micron-scale spot sizes. The processing overhead for this architecture remains relatively constant, even with large numbers of qubits, enabling scalable large-scale quantum information processing.

Abstract: Methods and systems are described for precisely adjusting characteristics of microfabricated devices after device fabrication. The adjustments can be carried out in parallel on a plurality of the microfabricated devices. By carrying out the adjustment process, uniformity of feature sizes to a few picometers (one standard deviation) and corresponding uniformity of operating characteristics for a plurality of microfabricated devices are possible.

Abstract: A spatial light modulator (SLM) comprised of a 2D array of optically-controlled semiconductor nanocavities can have a fast modulation rate, small pixel pitch, low pixel tuning energy, and millions of pixels. Incoherent pump light from a control projector tunes each PhC cavity via the free-carrier dispersion effect, thereby modulating the coherent probe field emitted from the cavity array. The use of high-Q/V semiconductor cavities enables energy-efficient all-optical control and eliminates the need for individual tuning elements, which degrade the performance and limit the size of the optical surface. Using this technique, an SLM with 106 pixels, micron-order pixel pitch, and GHz-order refresh rates could be realized with less than 1 W of pump power.

Abstract: Quantum information processing involves entangling large numbers of qubits, which can be realized as defect centers in a solid-state host. The qubits can be implemented as individual unit cells, each with its own control electronics, that are arrayed in a cryostat. Free-space control and pump beams address the qubit unit cells through a cryostat window. The qubit unit cells emit light in response to these control and pump beams and microwave pulses applied by the control electronics. The emitted light propagates through free space to a mode mixer, which interferes the optical modes from adjacent qubit unit cells for heralded Bell measurements. The qubit unit cells are small (e.g., 10 ?m square), so they can be tiled in arrays of up to millions, addressed by free-space optics with micron-scale spot sizes. The processing overhead for this architecture remains relatively constant, even with large numbers of qubits, enabling scalable large-scale quantum information processing.

Abstract: An all-photonic computational accelerator encodes information in the amplitudes of frequency modes stored in a ring resonator. Nonlinear optical processes enable interaction among these modes. Both the matrix multiplication and element-wise activation functions on these modes (the artificial neurons) occur through coherent processes, enabling the representation of negative and complex numbers without digital electronics. This accelerator has a lower hardware footprint than electronic and optical accelerators, as the matrix multiplication happens in a single multimode resonator on chip. Our architecture provides a unitary, reversible mode of computation, enabling on-chip analog Hamiltonian-echo backpropagation for gradient descent and other self-learning tasks. Moreover, the computational speed increases with the power of the pumps to arbitrarily high rates, as long as the circuitry can sustain the higher optical power.

Abstract: A spectrally multiplexed quantum repeater (SMuQR) based on spatially arrayed nodes of frequency-multiplexed multi-qubit registers uses the natural inhomogeneous distribution of optical transition frequencies in solid state defect centers. This distribution enables spectrally selective, individual addressing of large numbers of defect centers within an optical diffraction limited spot along a long cavity or waveguide. The spectral selection relies on frequency shifting an incident optical field at a rate as fast as once per defect center lifetime. The defect centers are resonant at visible frequencies and emit visible single photons which are down-converted to a wavelength compatible with long-distance transmission via conventional optical fiber. The down-converted photons are all at the same telecommunications wavelength, with the different spectral bins mapped to different temporal bins to preserve the multiplexing in the time domain, for distribution to other nodes in the quantum network.

Abstract: We disclose optical entanglement distribution in quantum networks based on a quasi-deterministic entangled photon pair source. Combining heralded photonic Bell pair generation with spectral mode conversion to interface with quantum memories eliminates switching losses due to multiplexing in the source. This zero-added-loss multiplexing (ZALM) Bell pair source is especially useful for the particularly challenging problem of long-baseline entanglement distribution via satellites and ground-based memories, where it unlocks additional advantages: (i) the substantially higher channel efficiency ? of downlinks versus uplinks with realistic adaptive optics, and (ii) photon loss occurring before interaction with the quantum memory—i.e., Alice and Bob receiving rather than transmitting—improve entanglement generation rate scaling by (?{square root over (?)}).