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公开(公告)号：US12174018B2
公开(公告)日：2024-12-24
申请号：US17711640
申请日：2022-04-01
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.
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公开(公告)号：US11112564B2
公开(公告)日：2021-09-07
申请号：US16827795
申请日：2020-03-24
Applicant: Massachusetts Institute of Technology
Inventor： Gregory R. Steinbrecher , Dirk Robert Englund
Abstract: A method of nonblocking optical switching includes guiding a first optical beam from a first input to a first output via a first path through an optical switching fabric. The first path traverses a phase shifter disposed between a pair of cascaded Mach-Zehnder interferometers. The method also includes receiving a second optical beam for a second path intersecting with the first path through the optical switching fabric. The method also includes moving the first optical beam from the first path to a third path connecting the first input to the first output without intersecting the second path. The method also includes shifting a phase of the first optical beam, with the phase shifter, while moving the first optical beam from the first path to the third path to prevent the first optical beam from interfering with the second optical beam.
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公开(公告)号：US10522326B2
公开(公告)日：2019-12-31
申请号：US15896377
申请日：2018-02-14
Applicant: Massachusetts Institute of Technology
Inventor： Michael Patrick Walsh , Dirk Robert Englund
IPC: H01J37/302 , H01L27/146 , H01J37/28 , H01J37/22 , G01N21/00 , G02B21/00 , H01L21/68 , H01L23/544
Abstract: A method of locating a substrate within a field of view of an imaging system includes acquiring an image of a first marker on a substrate in the field of view. The first marker has a first spatial pattern representing a position of the first marker relative to the substrate. The method also includes determining possible positions of the substrate based on the first spatial pattern and moving the substrate relative to the field of view based on the possible positions of the substrate. The method also includes acquiring an image of a second marker on the substrate in the field of view. The second marker has a second pattern representing a position of the second marker relative to the substrate. The method further includes determining the position of the substrate relative to the field of view based on the position of the second marker on the substrate.
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公开(公告)号：US10429718B2
公开(公告)日：2019-10-01
申请号：US15792066
申请日：2017-10-24
Applicant: Massachusetts Institute of Technology
Inventor： Mihir Pant , Dirk Robert Englund , Mikkel Heuck
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.
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公开(公告)号：US10312387B2
公开(公告)日：2019-06-04
申请号：US15436372
申请日：2017-02-17
Applicant: Massachusetts Institute of Technology
Inventor： Dirk Robert Englund
IPC: H01L31/0232 , G02F1/35 , H01L31/0304 , H04B10/70 , G01J1/44
Abstract: A single photon detector (SPD) includes a resonator to store probe photons at a probe wavelength and an absorber disposed in the resonator to absorb a signal photon at a signal wavelength. The absorber is also substantially transparent to the probe photons. In the absence of the signal photon, the resonator is on resonance with the probe photons, thereby confining the probe photons within the resonator. Absorption of the signal photon by the absorber disturbs the resonant condition of the resonator, causing the resonator to release multiple probe photons. A photodetector (PD) then detects these multiple probe photons to determine the presence of the signal photon.
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Patent Agency Ranking
公开(公告)号：US20190145919A1
公开(公告)日：2019-05-16
申请号：US16232137
申请日：2018-12-26
Applicant: Massachusetts Institute of Technology
Inventor： Hannah A. Clevenson , Dirk Robert Englund
Abstract: A light-trapping geometry enhances the sensitivity of strain, temperature, and/or electromagnetic field measurements using nitrogen vacancies in bulk diamond, which have exterior dimensions on the order of millimeters. In an example light-trapping geometry, a laser beam enters the bulk diamond, which may be at room temperature, through a facet or notch. The beam propagates along a path inside the bulk diamond that includes many total internal reflections off the diamond's surfaces. The NVs inside the bulk diamonds absorb the beam as it propagates. Photodetectors measure the transmitted beam or fluorescence emitted by the NVs. The resulting transmission or emission spectrum represents the NVs' quantum mechanical states, which in turn vary with temperature, magnetic field strength, electric field strength, strain/pressure, etc.
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公开(公告)号：US10197515B2
公开(公告)日：2019-02-05
申请号：US14325937
申请日：2014-07-08
Applicant: Massachusetts Institute of Technology
Inventor： Hannah A. Clevenson , Dirk Robert Englund
Abstract: A light-trapping geometry enhances the sensitivity of strain, temperature, and/or electromagnetic field measurements using nitrogen vacancies in bulk diamond, which have exterior dimensions on the order of millimeters. In an example light-trapping geometry, a laser beam enters the bulk diamond, which may be at room temperature, through a facet or notch. The beam propagates along a path inside the bulk diamond that includes many total internal reflections off the diamond's surfaces. The NVs inside the bulk diamonds absorb the beam as it propagates. Photodetectors measure the transmitted beam or fluorescence emitted by the NVs. The resulting transmission or emission spectrum represents the NVs' quantum mechanical states, which in turn vary with temperature, magnetic field strength, electric field strength, strain/pressure, etc.
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公开(公告)号：US12079693B2
公开(公告)日：2024-09-03
申请号：US18493257
申请日：2023-10-24
Applicant: Massachusetts Institute of Technology
Inventor： Hyeongrak Choi , Dirk Robert Englund
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 μm 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.
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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
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.
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公开(公告)号：US12019130B2
公开(公告)日：2024-06-25
申请号：US17465895
申请日：2021-09-03
Applicant: Massachusetts Institute of Technology
Inventor： Dirk Robert Englund
CPC classification number: G01R33/46 , G01R33/282 , G01R33/31 , G01R33/323
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. Tens to hundreds of small, cryogenically cooled sample chambers can be integrated in a semiconductor substrate interlaced with waveguides that contain color centers for optically detected magnetic resonance measurements of the samples' chemical-shift NMR frequencies.
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