Patents by Inventor Sujith Chandran

Sujith Chandran has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 12726201
    Abstract: An optical circuit includes a resonator including a nonlinear optical material having intensity-dependent absorption, an input, and an output. The optical circuit includes an optical input path coupled to the input of the resonator and provides an optical logic input, an optical reference path coherently coupled to the resonator and configured to provide a first reference signal coupled to the optical input path and a second reference signal, and an optical output path coupled to the output of the resonator and configured to receive the second reference signal. The resonator receives a combined version of the optical logic input and the first reference signal, and provides an optical output signal based on the optical logic input, the first reference signal, and an intensity threshold of the nonlinear optical material. The optical output path provides an optical logic output corresponding to an output logic state based on the optical output signal and the second reference signal.
    Type: Grant
    Filed: December 18, 2024
    Date of Patent: September 1, 2026
    Assignees: University of Southern California, The Regents of the University of California
    Inventors: John Bowers, Sujith Chandran, Yeshaiahu Fainman, Michael Haney, Ajey P. Jacob, Sugeet Sunder
  • Patent number: 12687675
    Abstract: Structures for a photonics chip that include a photodetector and methods of forming such structures. The structure comprises a photodetector, a first waveguide core coupled to the photodetector, and a second waveguide core coupled to the photodetector. The structure further comprises a third waveguide core including a section disposed laterally between a section of the first waveguide core and a section of the second waveguide core.
    Type: Grant
    Filed: December 11, 2023
    Date of Patent: July 21, 2026
    Assignee: GlobalFoundries U.S. Inc.
    Inventors: Sujith Chandran, Yusheng Bian, Abdelsalam Aboketaf, Won Suk Lee
  • Patent number: 12671157
    Abstract: Structures for a phase shifter and methods of forming such structures. The structure comprises a phase shifter including a first section, a second section, and a strip laterally between the first section and the second section. The structure further comprises a waveguide core including a portion laterally between the first section and the second section of the phase shifter, and a dielectric layer between the waveguide core and the phase shifter. The strip is laterally offset relative to the portion of the waveguide core toward the first section of the phase shifter.
    Type: Grant
    Filed: August 2, 2024
    Date of Patent: June 30, 2026
    Assignee: GlobalFoundries U.S. Inc.
    Inventors: Aneesh Dash, Riddhi Nandi, Avijit Chatterjee, Yusheng Bian, Pratyasha Priyadarshini, Sujith Chandran, Rupa Gopinath Minasamudram, Vaibhav Anantrai Ruparelia
  • Patent number: 12625320
    Abstract: Structures for a photonics chip that include a photodetector and methods of forming such structures. The structure comprises a photodetector including a pad and a semiconductor layer on the pad. The structure further comprises a waveguiding structure including a first waveguide core, a second waveguide core, a slot between the first waveguide core and the second waveguide core, and a plurality of waveguide core segments. The waveguiding structure is adjoined to a side edge of the pad adjacent to the semiconductor layer. Each of the plurality of waveguide core segments includes a portion that is disposed in the slot.
    Type: Grant
    Filed: January 10, 2024
    Date of Patent: May 12, 2026
    Assignee: GlobalFoundries U.S. Inc.
    Inventors: Yusheng Bian, Won Suk Lee, Sujith Chandran, Abdelsalam Aboketaf
  • Patent number: 12619026
    Abstract: Structures for a waveguide escalator, as well as methods of forming such structures. The structure comprises a first waveguide core on a substrate, a second waveguide core, and a back-end-of-line stack including a third waveguide core disposed between the first waveguide core and the second waveguide core. The third waveguide core comprises a layer stack that includes a first layer, a second layer, and a third layer between the first layer and the second layer. The first layer and the second layer comprise a first dielectric material with a first refractive index, and the third layer comprises a second dielectric material with a second refractive index that is less than the first refractive index.
    Type: Grant
    Filed: December 20, 2023
    Date of Patent: May 5, 2026
    Assignee: GlobalFoundries U.S. Inc.
    Inventors: Avijit Chatterjee, Yusheng Bian, Sujith Chandran, Aneesh Dash, Michal Rakowski, Riddhi Nandi, Kenneth J. Giewont, Theodore Letavic, Mehrdad Djavid, Ravi Prakash Srivastava
  • Patent number: 12601937
    Abstract: Structures for a thermo-optic phase shifter and methods of forming a thermo-optic phase shifter. The structure comprises an interconnect structure including a dielectric layer, a waveguide core on the dielectric layer, and a heater on the dielectric layer. The heater includes a resistive heating element positioned adjacent to the waveguide core.
    Type: Grant
    Filed: May 23, 2023
    Date of Patent: April 14, 2026
    Assignee: GlobalFoundries U.S. Inc.
    Inventors: Brian McGowan, Ping-Chuan Wang, Michal Rakowski, Sujith Chandran, Yusheng Bian
  • Patent number: 12572048
    Abstract: Structures for a broadband optical switch and methods of forming such structures. The structure comprises a Mach-Zehnder interferometer including first and second arms. The first arm comprises a first waveguide core, and the second arm comprises a second waveguide core. The structure further comprises a ring resonator comprising a third waveguide core that has a first thickness. A portion of the third waveguide core is adjacent to a portion of the first waveguide core over a light coupling region. A slab layer connects the portion of the first waveguide core to the portion of the third waveguide core. The slab layer has a second thickness that is less than the first thickness of the first waveguide core.
    Type: Grant
    Filed: June 15, 2023
    Date of Patent: March 10, 2026
    Assignee: GlobalFoundries U.S. Inc.
    Inventors: Michal Rakowski, Sujith Chandran, Takako Hirokawa, Pilar Gonzalez
  • Publication number: 20260036749
    Abstract: Structures for a wavelength-division-multiplexing filter and methods of forming a structure for a wavelength-division-multiplexing filter. The structure comprises a first waveguide core including a first phase delay arm and a second waveguide core including a second phase delay arm. The first phase delay arm has a first section and a second section connected to the first section. The first section of the first phase delay arm and the second section of the first phase delay arm are asymmetrical.
    Type: Application
    Filed: July 31, 2024
    Publication date: February 5, 2026
    Inventors: Aneesh Dash, Sujith Chandran, Yusheng Bian, Avijit Chatterjee, Won Suk Lee, Michal Rakowski
  • Publication number: 20260038999
    Abstract: Structures for a phase shifter and methods of forming such structures. The structure comprises a phase shifter including a first section, a second section, and a strip laterally between the first section and the second section. The structure further comprises a waveguide core including a portion laterally between the first section and the second section of the phase shifter, and a dielectric layer between the waveguide core and the phase shifter. The strip is laterally offset relative to the portion of the waveguide core toward the first section of the phase shifter.
    Type: Application
    Filed: August 2, 2024
    Publication date: February 5, 2026
    Inventors: Aneesh Dash, Riddhi Nandi, Avijit Chatterjee, Yusheng Bian, Pratyasha Priyadarshini, Sujith Chandran, Rupa Gopinath Minasamudram, Vaibhav Anantrai Ruparelia
  • Publication number: 20260016631
    Abstract: Structures for a photonic chip that include a photonic component and delay lines and methods of forming such structures. The structure comprises a photonic component, a first waveguide core including a section coupled to the photonic component, and a second waveguide core including a section coupled to the photonic component. The section of the first waveguide core has a first length, and the section of the second waveguide core having a second length that is greater than the first length.
    Type: Application
    Filed: July 15, 2024
    Publication date: January 15, 2026
    Inventors: Sujith Chandran, Yusheng Bian, Won Suk Lee, Abdelsalam Aboketaf
  • Patent number: 12504653
    Abstract: Structures for a thermo-optic phase shifter and methods of forming a thermo-optic phase shifter. The structure comprises a semiconductor substrate, and a heater including a first resistive heating element, a second resistive heating element, and a slab layer connecting the first resistive heating element to the second resistive heating element. The first resistive heating element and the second resistive heating element have a first thickness, and the slab layer has a second thickness that is less than the first thickness. The structure further comprises a waveguide core including a portion that is laterally positioned between the first resistive heating element and the second resistive heating element. The slab layer of the heater is disposed between the portion of the waveguide core and the semiconductor substrate.
    Type: Grant
    Filed: May 24, 2023
    Date of Patent: December 23, 2025
    Assignee: GlobalFoundries U.S. Inc.
    Inventors: Sujith Chandran, Yusheng Bian, Won Suk Lee
  • Publication number: 20250328055
    Abstract: Structures for a modulator and methods of forming a structure for a modulator. The structure comprises a first waveguide core including a delay section, and a second waveguide core including a delay section. The delay section of the second waveguide core has a shorter length than the delay section of the first waveguide core. The structure further comprises an optical phase shifter including a p-n junction in a portion of the delay section of the first waveguide core.
    Type: Application
    Filed: April 18, 2024
    Publication date: October 23, 2025
    Inventors: Sujith Chandran, Yusheng Bian, Won Suk Lee, Abdelsalam Aboketaf
  • Patent number: 12444462
    Abstract: An electro-optic random-access memory enables (1) ultra-fast write and read operation (2) featuring differential sensing (3) wavelength, and polarization multiplex high bandwidth memory access (4) enables very large-scale memory array for wafer scale ICs.
    Type: Grant
    Filed: March 14, 2022
    Date of Patent: October 14, 2025
    Assignee: University of Southern California
    Inventors: Ajey Poovannummoottil Jacob, Akhilesh Ramlaut Jaiswal, Ramesh Kudalippalliyalil, Sujith Chandran
  • Patent number: 12360319
    Abstract: Provided is an electro-optic transducer comprising: a first optical disk resonator and a second optical disk resonator, wherein the first optical disk resonator and the second optical disk resonator are optically coupled; a waveguide, the waveguide optically coupled to at least one of the first optical disk resonator and the second optical disk resonator; and a resonator, the resonator functionally coupled to at least a portion of the first optical disk resonator and the second optical disk resonator.
    Type: Grant
    Filed: December 1, 2022
    Date of Patent: July 15, 2025
    Assignee: UNIVERSITY OF SOUTHERN CALIFORNIA
    Inventors: Ramesh Kudalippalliyalil, Sujith Chandran, Akhilesh Jaiswal, Ajey P. Jacob
  • Publication number: 20250224560
    Abstract: Structures for a photonics chip that include a photodetector and methods of forming such structures. The structure comprises a photodetector including a pad and a semiconductor layer on the pad. The structure further comprises a waveguiding structure including a first waveguide core, a second waveguide core, a slot between the first waveguide core and the second waveguide core, and a plurality of waveguide core segments. The waveguiding structure is adjoined to a side edge of the pad adjacent to the semiconductor layer. Each of the plurality of waveguide core segments includes a portion that is disposed in the slot.
    Type: Application
    Filed: January 10, 2024
    Publication date: July 10, 2025
    Inventors: Yusheng Bian, Won Suk Lee, Sujith Chandran, Abdelsalam Aboketaf
  • Publication number: 20250224578
    Abstract: Structures for a photonics chip that include a photodetector and methods of forming such structures. The structure comprises a photodetector including a pad and a semiconductor layer on the pad. The pad includes a side edge and a first waveguide core that extends from the side edge adjacent to the semiconductor layer. The structure further comprises a second waveguide core including a section adjoined to the side edge of the pad adjacent to the first waveguide core.
    Type: Application
    Filed: January 5, 2024
    Publication date: July 10, 2025
    Inventors: Yusheng Bian, Sujith Chandran, Won Suk Lee, Abdelsalam Aboketaf
  • Publication number: 20250211234
    Abstract: An optical circuit includes a resonator including a nonlinear optical material having intensity-dependent absorption, an input, and an output. The optical circuit includes an optical input path coupled to the input of the resonator and provides an optical logic input, an optical reference path coherently coupled to the resonator and configured to provide a first reference signal coupled to the optical input path and a second reference signal, and an optical output path coupled to the output of the resonator and configured to receive the second reference signal. The resonator receives a combined version of the optical logic input and the first reference signal, and provides an optical output signal based on the optical logic input, the first reference signal, and an intensity threshold of the nonlinear optical material. The optical output path provides an optical logic output corresponding to an output logic state based on the optical output signal and the second reference signal.
    Type: Application
    Filed: December 18, 2024
    Publication date: June 26, 2025
    Inventors: John Bowers, Sujith Chandran, Yeshaiahu Fainman, Michael Haney, Ajey P. Jacob, Sugeet Sunder
  • Publication number: 20250208341
    Abstract: Structures for a waveguide escalator, as well as methods of forming such structures. The structure comprises a first waveguide core on a substrate, a second waveguide core, and a back-end-of-line stack including a third waveguide core disposed between the first waveguide core and the second waveguide core. The third waveguide core comprises a layer stack that includes a first layer, a second layer, and a third layer between the first layer and the second layer. The first layer and the second layer comprise a first dielectric material with a first refractive index, and the third layer comprises a second dielectric material with a second refractive index that is less than the first refractive index.
    Type: Application
    Filed: December 20, 2023
    Publication date: June 26, 2025
    Inventors: Avijit Chatterjee, Yusheng Bian, Sujith Chandran, Aneesh Dash, Michal Rakowski, Riddhi Nandi, Kenneth J. Giewont, Theodore Letavic, Mehrdad Djavid, Ravi Prakash Srivastava
  • Publication number: 20250189721
    Abstract: Structures for a photonics chip that include a photodetector and methods of forming such structures. The structure comprises a photodetector, a first waveguide core coupled to the photodetector, and a second waveguide core coupled to the photodetector. The structure further comprises a third waveguide core including a section disposed laterally between a section of the first waveguide core and a section of the second waveguide core.
    Type: Application
    Filed: December 11, 2023
    Publication date: June 12, 2025
    Inventors: Sujith Chandran, Yusheng Bian, Abdelsalam Aboketaf, Won Suk Lee
  • Publication number: 20250147235
    Abstract: Structures for a photonics chip that include a photodetector and methods of forming such structures. The structure comprises a photodetector that is disposed on a substrate and that includes a light-absorbing layer. The light-absorbing layer includes a sidewall and a notch in the sidewall. The structure further comprises a waveguide core including a section adjacent to the notch in the sidewall of the light-absorbing layer.
    Type: Application
    Filed: November 3, 2023
    Publication date: May 8, 2025
    Inventors: Yusheng Bian, Andreas D. Stricker, Abdelsalam Aboketaf, Judson R. Holt, Kevin K. Dezfulian, Kenneth J. Giewont, Alexander Derrickson, Won Suk Lee, Sujith Chandran, Ryan W. Sporer, Teng-Yin Lin