Abstract: Systems and methods for hybrid integration of ultra-low loss waveguide photonic circuits with various efficient on-chip elements are described. The photonic circuits can integrate various elements including (but not limited to): gain, modulation, detection, and nonlinear optical elements. The integrated photonic chips can be manufactured in a flexible, reconfigurable, 3D heterogeneous platform. The integrated photonic chips can cover wavelength ranges from the visible wavelength to infrared wavelength.

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: Provided herein is a photonic modulator and methods for controlling a photonic modulator that can control the phase and/or amplitude of photons being transmitted through the modulator to minimize photonic loss while remaining power efficient and operating at high speeds. The photonic modulator can include a substrate with a pair of piezoelectric cantilevers spaced apart from one another by a gap, with a photonic waveguide disposed in the substrate that extends across the modulator and bridges the gap between the piezoelectric cantilevers. In one or more examples, the piezoelectric cantilevers can be configured to move away from the substrate in response to an electrical signal, such that a refractive index of the photonic waveguide is altered.

Abstract: A two-photon logic gate introduces a phase shift between two photons using a Q-switched cavity with some nonlinearity. The two-photon logic gate catches photons in and releases photons from de-coupled cavity modes in response to electronic or photonic control signals. This “catch-and-release” two-photon gate can be formed in semiconductor photonic integrated circuit (PIC) that operates at room temperature. When combined with sources, linear circuits, other logic gates, and detectors, it can be used to make a quantum computer with up to 1000 error-corrected logical qubits on a cm2 PIC, with full qubit connectivity to avoid overhead. Two-qubit gate fidelity exceeding 99% is possible with near-term technology, and scaling beyond 99.9% is possible. Two-photon logic gates are also suitable for gate-based quantum digital computing and for analog quantum computing schemes, such as adiabatic quantum computing or quantum annealing.

Abstract: A two-photon logic gate introduces a phase shift between two photons using a Q-switched cavity with some nonlinearity. The two-photon logic gate catches photons in and releases photons from de-coupled cavity modes in response to electronic or photonic control signals. This “catch-and-release” two-photon gate can be formed in semiconductor photonic integrated circuit (PIC) that operates at room temperature. When combined with sources, linear circuits, other logic gates, and detectors, it can be used to make a quantum computer with up to 1000 error-corrected logical qubits on a cm2 PIC, with full qubit connectivity to avoid overhead. Two-qubit gate fidelity exceeding 99% is possible with near-term technology, and scaling beyond 99.9% is possible. Two-photon logic gates are also suitable for gate-based quantum digital computing and for analog quantum computing schemes, such as adiabatic quantum computing or quantum annealing.

Abstract: A photon source to deliver single photons includes a storage ring resonator to receive pump photons and generate a signal photon and an idler photon. An idler resonator is coupled to the storage resonator to couple the idler photon out of the storage resonator and into a detector. Detection of the idler photon stops the pump photons from entering the storage resonator. A signal resonator is coupled to the storage resonator to couple out the signal photon remaining in the storage resonator and delivers the signal photon to applications. The photon source can be fabricated into a photonic integrated circuit to achieve high compactness, reliability, and controllability.

Abstract: A large-scale tunable-coupling ring array includes an input waveguide coupled to multiple ring resonators, each of which has a distinct resonant wavelength. The collective effect of these multiple ring resonators is to impart a distinct time delay to a distinct wavelength component (or frequency component) in an input signal, thereby carrying out quantum scrambling of the input signal. The scrambled signal is received by a receiver also using a large-scale tunable-coupling ring array. This receiver-end ring resonator array recovers the input signal by imparting a compensatory time delay to each wavelength component. Each ring resonator can be coupled to the input waveguide via a corresponding Mach Zehnder interferometer (MZI). The MZI includes a phase shifter on at least one of its arms to increase the tunability of the ring array.

Abstract: A photon source to deliver single photons includes a storage ring resonator to receive pump photons and generate a signal photon and an idler photon. An idler resonator is coupled to the storage resonator to couple the idler photon out of the storage resonator and into a detector. Detection of the idler photon stops the pump photons from entering the storage resonator. A signal resonator is coupled to the storage resonator to couple out the signal photon remaining in the storage resonator and delivers the signal photon to applications. The photon source can be fabricated into a photonic integrated circuit to achieve high compactness, reliability, and controllability.

Abstract: A photon source to deliver single photons includes a storage ring resonator to receive pump photons and generate a signal photon and an idler photon. An idler resonator is coupled to the storage resonator to couple the idler photon out of the storage resonator and into a detector. Detection of the idler photon stops the pump photons from entering the storage resonator. A signal resonator is coupled to the storage resonator to couple out the signal photon remaining in the storage resonator and delivers the signal photon to applications. The photon source can be fabricated into a photonic integrated circuit to achieve high compactness, reliability, and controllability.

Abstract: A large-scale tunable-coupling ring array includes an input waveguide coupled to multiple ring resonators, each of which has a distinct resonant wavelength. The collective effect of these multiple ring resonators is to impart a distinct time delay to a distinct wavelength component (or frequency component) in an input signal, thereby carrying out quantum scrambling of the input signal. The scrambled signal is received by a receiver also using a large-scale tunable-coupling ring array. This receiver-end ring resonator array recovers the input signal by imparting a compensatory time delay to each wavelength component. Each ring resonator can be coupled to the input waveguide via a corresponding Mach Zehnder interferometer (MZI). The MZI includes a phase shifter on at least one of its arms to increase the tunability of the ring array.

Abstract: A photon source to deliver single photons includes a storage ring resonator to receive pump photons and generate a signal photon and an idler photon. An idler resonator is coupled to the storage resonator to couple the idler photon out of the storage resonator and into a detector. Detection of the idler photon stops the pump photons from entering the storage resonator. A signal resonator is coupled to the storage resonator to couple out the signal photon remaining in the storage resonator and delivers the signal photon to applications. The photon source can be fabricated into a photonic integrated circuit to achieve high compactness, reliability, and controllability.