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: 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: 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: 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: Photonic chip includes an external cavity (EC) optical circuit to provide wavelength-selective optical feedback to a length of active optical fiber. Light generated in the active optical fiber may be coupled from the EC circuit to a light processing circuit of the photonic chip, such as an optical modulator or an optical mixer. The EC circuits may include single-frequency and multi-frequency optical filters, which may include ring resonators, dual-ring resonators, and optical modulators to support multi-frequency lasers. The EC circuits may further include pump combiners and optical isolators.

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: 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: Photonic chip includes an external cavity (EC) optical circuit to provide wavelength-selective optical feedback to a length of active optical fiber. Light generated in the active optical fiber may be coupled from the EC circuit to a light processing circuit of the photonic chip, such as an optical modulator or an optical mixer. The EC circuits may include single-frequency and multi-frequency optical filters, which may include ring resonators, dual-ring resonators, and optical modulators to support multi-frequency lasers. The EC circuits may further include pump combiners and optical isolators.

Abstract: Room temperature IR and UV photodetectors are provided by electrochemical self-assembly of nanowires. The detectivity of such IR detectors is up to ten times better than the state of the art. Broad peaks are observed in the room temperature absorption spectra of 10-nm diameter nanowires of CdSe and ZnS at photon energies close to the bandgap energy, indicating that the detectors are frequency selective and preferably detect light of specific frequencies. Provided is a photodetector comprising: an aluminum substrate; a layer of insulator disposed on the aluminum substrate and comprising an array of columnar pores; a plurality of semiconductor nanowires disposed within the pores and standing vertically relative to the aluminum substrate; a layer of nickel disposed in operable communication with one or more of the semiconductor nanowires; and wire leads in operable communication with the aluminum substrate and the layer of nickel for connection with an electrical circuit.

Abstract: Room temperature IR and UV photodetectors are provided by electrochemical self-assembly of nanowires. The detectivity of such IR detectors is up to ten times better than the state of the art. Broad peaks are observed in the room temperature absorption spectra of 10-nm diameter nanowires of CdSe and ZnS at photon energies close to the bandgap energy, indicating that the detectors are frequency selective and preferably detect light of specific frequencies. Provided is a photodetector comprising: an aluminum substrate; a layer of insulator disposed on the aluminum substrate and comprising an array of columnar pores; a plurality of semiconductor nanowires disposed within the pores and standing vertically relative to the aluminum substrate; a layer of nickel disposed in operable communication with one or more of the semiconductor nanowires; and wire leads in operable communication with the aluminum substrate and the layer of nickel for connection with an electrical circuit.