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公开(公告)号：US10571483B2
公开(公告)日：2020-02-25
申请号：US15807531
申请日：2017-11-08
Applicant: Massachusetts Institute of Technology
Inventor： Suraj Deepak Bramhavar , Paul William Juodawlkis
IPC: G01P15/093 , G01P15/03 , G01P15/097 , G01P21/00
Abstract: An accelerometer may comprise a proof mass, a first tether mechanically coupled to the side of the proof mass and to an anchor, and a ring resonator integrated with the tether to form a sensing tether. The ring resonator and the tether may be configured such that a strain sustained by the sensing tether causes a change of a resonance condition of the ring resonator. The accelerometer may comprise a wavelength locking loop configured to adaptively maintain a center frequency of the light energy at a resonant frequency of the sensing element, and a scale factor calibrator configured to stabilize a scale factor associated with the accelerometer. The accelerometer may further include a detection processor configured to receive the detection signal and produce an acceleration signal therefrom. The acceleration signal may correspond to an amount of change of the resonance condition with respect to a reference resonance condition.
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公开(公告)号：US11340400B2
公开(公告)日：2022-05-24
申请号：US16809640
申请日：2020-03-05
Applicant: Massachusetts Institute of Technology
Inventor： Boris Kharas , Reuel B. Swint , Cheryl Marie Sorace-Agaskar , Paul William Juodawlkis , Suraj Deepak Bramhavar , Jason Plant
Abstract: Photonic integrated circuits (PICs) enable manipulation of light on a chip for telecommunications and information processing. They can be made with silicon and silicon-compatible materials using complementary metal-oxide-semiconductor (CMOS) fabrication techniques developed for making electronics. Unfortunately, most light sources are made with III-V and II-VI materials, which are not compatible with silicon CMOS fabrication techniques. As a result, the light source for a PIC is either off-chip or integrated onto the PIC after CMOS fabrication is over. Hybrid integration can be improved by forming a recess in the PIC to receive a III-V or II-VI photonic chip. Mechanical stops formed in or next to the recess during fabrication align the photonic chip vertically to the PIC. Fiducials on the PIC and the photonic chip enable sub-micron lateral alignment. As a result, the photonic chip can be flip-chip bonded to the PIC with sub-micron vertical and lateral alignment precision.
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Patent Agency Ranking
公开(公告)号：US11493530B2
公开(公告)日：2022-11-08
申请号：US16677842
申请日：2019-11-08
Applicant: Massachusetts Institute of Technology
Inventor： Suraj Deepak Bramhavar , Paul William Juodawlkis
IPC: G01P15/097 , H03H3/007 , G01P15/093 , H03H9/24 , H03H9/02
Abstract: The accelerometers disclosed herein provide excellent sensitivity, long-term stability, and low SWaP-C through a combination of photonic integrated circuit technology with standard micro-electromechanical systems (MEMS) technology. Examples of these accelerometers use optical transduction to improve the scale factor of traditional MEMS resonant accelerometers by accurately measuring the resonant frequencies of very small (e.g., about 1 μm) tethers attached to a large (e.g., about 1 mm) proof mass. Some examples use ring resonators to measure the tether frequencies and some other examples use linear resonators to measure the tether frequencies. Potential commercial applications span a wide range from seismic measurement systems to automotive stability controls to inertial guidance to any other application where chip-scale accelerometers are currently deployed.
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公开(公告)号：US10649306B2
公开(公告)日：2020-05-12
申请号：US16284161
申请日：2019-02-25
Applicant: Massachusetts Institute of Technology
Inventor： Scott A. Skirlo , Cheryl Marie Sorace-Agaskar , Marin Soljacic , Simon Verghese , Jeffrey S. Herd , Paul William Juodawlkis , Yi Yang , Dirk Robert Englund , Mihika Prabhu
Abstract: An integrated optical beam steering device includes a planar dielectric lens that collimates beams from different inputs in different directions within the lens plane. It also includes an output coupler, such as a grating or photonic crystal, that guides the collimated beams in different directions out of the lens plane. A switch matrix controls which input port is illuminated and hence the in-plane propagation direction of the collimated beam. And a tunable light source changes the wavelength to control the angle at which the collimated beam leaves the plane of the substrate. The device is very efficient, in part because the input port (and thus in-plane propagation direction) can be changed by actuating only log2 N of the N switches in the switch matrix. It can also be much simpler, smaller, and cheaper because it needs fewer control lines than a conventional optical phased array with the same resolution.
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公开(公告)号：US11175562B2
公开(公告)日：2021-11-16
申请号：US16842048
申请日：2020-04-07
Applicant: Massachusetts Institute of Technology
Inventor： Scott A. Skirlo , Cheryl Marie Sorace-Agaskar , Marin Soljacic , Simon Verghese , Jeffrey S. Herd , Paul William Juodawlkis , Yi Yang , Dirk Englund , Mihika Prabhu
Abstract: An integrated optical beam steering device includes a planar dielectric lens that collimates beams from different inputs in different directions within the lens plane. It also includes an output coupler, such as a grating or photonic crystal, that guides the collimated beams in different directions out of the lens plane. A switch matrix controls which input port is illuminated and hence the in-plane propagation direction of the collimated beam. And a tunable light source changes the wavelength to control the angle at which the collimated beam leaves the plane of the substrate. The device is very efficient, in part because the input port (and thus in-plane propagation direction) can be changed by actuating only log2 N of the N switches in the switch matrix. It can also be much simpler, smaller, and cheaper because it needs fewer control lines than a conventional optical phased array with the same resolution.
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公开(公告)号：US11050214B2
公开(公告)日：2021-06-29
申请号：US16401750
申请日：2019-05-02
Applicant: Massachusetts Institute of Technology
Inventor： William Loh , Paul William Juodawlkis , Siva Yegnanarayanan
IPC: H01S3/30 , H01S3/094 , H01S3/13 , H01S3/131 , H01S3/23 , H01S5/0687 , H01S3/0941 , H01S3/10
Abstract: In an ultrastable laser, using a large mode-volume optical resonator, which suppresses the resonator's fast thermal fluctuations, together with the stimulated Brillouin scattering (SBS) optical nonlinearity presents a powerful combination that enables the ability to lase with an ultra-narrow linewidth of 20 Hz. The laser's long-term temperature drift is compensated by using the narrow Brillouin line to sense minute changes in the resonator's temperature (e.g., changes of 85 nK). The precision of this temperature measurement enables the stabilization of resonators against environmental perturbations.
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公开(公告)号：US20180128850A1
公开(公告)日：2018-05-10
申请号：US15807531
申请日：2017-11-08
Applicant: Massachusetts Institute of Technology
Inventor： Suraj Deepak Bramhavar , Paul William Juodawlkis
IPC: G01P15/093 , G01P15/097 , G01P15/03
CPC classification number: G01P15/093 , G01P15/032 , G01P15/097 , G01P21/00
Abstract: An accelerometer may comprise a proof mass, a first tether mechanically coupled to the side of the proof mass and to an anchor, and a ring resonator integrated with the tether to form a sensing tether. The ring resonator and the tether may be configured such that a strain sustained by the sensing tether causes a change of a resonance condition of the ring resonator. The accelerometer may comprise a wavelength locking loop configured to adaptively maintain a center frequency of the light energy at a resonant frequency of the sensing element, and a scale factor calibrator configured to stabilize a scale factor associated with the accelerometer. The accelerometer may further include a detection processor configured to receive the detection signal and produce an acceleration signal therefrom. The acceleration signal may correspond to an amount of change of the resonance condition with respect to a reference resonance condition.
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