公开(公告)号：US12038608B2

公开(公告)日：2024-07-16

申请号：US17470803

申请日：2021-09-09

Applicant: Massachusetts Institute of Technology

Inventor： Saumil Bandyopadhyay ,  Dirk Robert Englund

IPC: G02B6/125 ,  G02B6/12

CPC classification number: G02B6/125 ,  G02B2006/12147

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. For example, it can be used in a self-aligning photonic circuit board that can be assembled more easily, with larger misalignment tolerances, than other complex optoelectronic systems.

公开(公告)号：US12175335B2

公开(公告)日：2024-12-24

申请号：US17556033

申请日：2021-12-20

Applicant: Massachusetts Institute of Technology

Inventor： Saumil Bandyopadhyay ,  Ryan Hamerly ,  Dirk Robert Englund

IPC: G06N10/70 ,  G02F1/21 ,  G06N10/40 ,  H04B10/70

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. Our error correction process can be used to scale up programmable photonics within current fabrication processes.

公开(公告)号：US12174018B2

公开(公告)日：2024-12-24

申请号：US17711640

申请日：2022-04-01

Applicant: Massachusetts Institute of Technology ,  NTT Research, Incorporated

Inventor： Ryan Hamerly ,  Saumil Bandyopadhyay ,  Dirk Robert Englund

IPC: G01B9/02055 ,  G01B9/02015

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. The configured photonic circuit can be used for machine learning, quantum photonics, prototyping, optical switching/multicast networks, microwave photonics, or signal processing.

公开(公告)号：US20250085100A1

公开(公告)日：2025-03-13

申请号：US18956238

申请日：2024-11-22

Applicant: Massachusetts Institute of Technology ,  NTT Research, Incorporated

Inventor： Ryan HAMERLY ,  Saumil Bandyopadhyay ,  Dirk Robert ENGLUND

IPC: G01B9/02055 ,  G01B9/02001

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. The configured photonic circuit can be used for machine learning, quantum photonics, prototyping, optical switching/multicast networks, microwave photonics, or signal processing.