Patents by Inventor Radhakrishnan L. Nagarajan

Radhakrishnan L. Nagarajan 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).

  • Publication number: 20210088739
    Abstract: An apparatus for dissipating heat from a photonic transceiver module. The apparatus includes a top-plate member disposed in a length direction of a package for the photonic transceiver module. The apparatus further includes multiple fins formed on the top-plate member along the length direction from a backend position to a frontend position except at least one fin with a shorter length, forming an elongated void from the backend position to one backend of the at least one fin. Additionally, the apparatus includes a cover member disposed over the multiple fins with a horizontal sheet, two vertical side sheets, and a flange bent vertically from a middle portion of backend of the horizontal sheet. Furthermore, the apparatus includes a spring loaded in the elongated void between the flange and the one backend of the at least one fin to minimize an air gap at the backend of the horizontal sheet.
    Type: Application
    Filed: November 11, 2020
    Publication date: March 25, 2021
    Inventors: Chris TOGAMI, Radhakrishnan L. NAGARAJAN, Gary SASSER, Brian TAYLOR
  • Publication number: 20210091536
    Abstract: A packaged transmitter device includes a base member comprising a planar part mounted with a thermoelectric cooler, a transmitter, and a coupling lens assembly, and an assembling part connected to one side of the planar part. The device further includes a circuit board bended to have a first end region and a second end region being raised to a higher level. The first end region disposed on a top surface of the planar part includes multiple electrical connection patches respectively connected to the thermoelectric and the transmitter. The second end region includes an electrical port for external connection. Additionally, the device includes a cover member disposed over the planar part. Furthermore, the device includes a cylindrical member installed to the assembling part for enclosing an isolator aligned to the coupling lens assembly along its axis and connected to a fiber to couple optical signal from the transmitter to the fiber.
    Type: Application
    Filed: December 8, 2020
    Publication date: March 25, 2021
    Inventors: Radhakrishnan L. NAGARAJAN, Peng-Chih LI, Pi-Cheng LAW
  • Publication number: 20210088738
    Abstract: An apparatus for dissipating heat from a photonic transceiver module. The apparatus includes a top-plate member disposed in a length direction of a package for the photonic transceiver module. The apparatus further includes multiple fins formed on the top-plate member along the length direction from a backend position to a frontend position except at least one fin with a shorter length, forming an elongated void from the backend position to one backend of the at least one fin. Additionally, the apparatus includes a cover member disposed over the multiple fins with a horizontal sheet, two vertical side sheets, and a flange bent vertically from a middle portion of backend of the horizontal sheet. Furthermore, the apparatus includes a spring loaded in the elongated void between the flange and the one backend of the at least one fin to minimize an air gap at the backend of the horizontal sheet.
    Type: Application
    Filed: September 20, 2019
    Publication date: March 25, 2021
    Inventors: Chris TOGAMI, Radhakrishnan L. NAGARAJAN, Gary SASSER, Brian TAYLOR
  • Patent number: 10951343
    Abstract: An integrated apparatus with optical/electrical interfaces and protocol converter on a single silicon substrate. The apparatus includes an optical module comprising one or more modulators respectively coupled with one or more laser devices for producing a first optical signal to an optical interface and one or more photodetectors for detecting a second optical signal from the optical interface to generate a current signal. Additionally, the apparatus includes a transmit lane module coupled between the optical module and an electrical interface to receive a first electric signal from the electrical interface and provide a framing protocol for driving the one or more modulators. Furthermore, the apparatus includes a receive lane module coupled between the optical module and the electrical interface to process the current signal to send a second electric signal to the electrical interface.
    Type: Grant
    Filed: July 10, 2020
    Date of Patent: March 16, 2021
    Assignee: INPHI CORPORATION
    Inventor: Radhakrishnan L. Nagarajan
  • Patent number: 10951003
    Abstract: A light source based on integrated silicon photonics includes a die of a silicon substrate having at least one chip site configured with a surface region, a trench region, and a first stopper region located separately between the surface region and the trench region. The trench region is configured to be a depth lower than the surface region. The light source includes a laser diode chip having a p-side facing the chip site and a n-side being distal to the chip site. The p-side includes a gain region bonded to the trench region, an electrode region bonded to the surface region, and an isolation region engaged with the stopper region to isolate the gain region from the electrode region. The light source also includes a conductor layer in the die configured to connect the gain region to an anode electrode and separately connect the electrode region to a cathode electrode.
    Type: Grant
    Filed: February 25, 2020
    Date of Patent: March 16, 2021
    Assignee: INPHI CORPORATION
    Inventors: Xiaoguang He, Radhakrishnan L. Nagarajan
  • Patent number: 10942323
    Abstract: An apparatus for dissipating heat from a photonic transceiver module. The apparatus includes a top-plate member disposed in a length direction of a package for the photonic transceiver module. The apparatus further includes multiple fins formed on the top-plate member along the length direction from a backend position to a frontend position except at least one fin with a shorter length, forming an elongated void from the backend position to one backend of the at least one fin. Additionally, the apparatus includes a cover member disposed over the multiple fins with a horizontal sheet, two vertical side sheets, and a flange bent vertically from a middle portion of backend of the horizontal sheet. Furthermore, the apparatus includes a spring loaded in the elongated void between the flange and the one backend of the at least one fin to minimize an air gap at the backend of the horizontal sheet.
    Type: Grant
    Filed: September 20, 2019
    Date of Patent: March 9, 2021
    Assignee: INPHI CORPORATION
    Inventors: Chris Togami, Radhakrishnan L. Nagarajan, Gary Sasser, Brian Taylor
  • Publication number: 20210058160
    Abstract: The present invention is directed to communication systems and methods. In a specific embodiment, the present invention provides an optical receiver that receives a data stream from an optical transmitter. The optical receiver determines a histogram contour parameter using the data stream and inserts the histogram contour parameter into a back-channel data segment, which is then transmitted to the optical transmitter. The optical transmitter changes its data transmission setting based on the histogram contour parameter. There are other embodiments as well.
    Type: Application
    Filed: November 5, 2020
    Publication date: February 25, 2021
    Inventors: Todd ROPE, Hari SHANKAR, Radhakrishnan L. NAGARAJAN
  • Publication number: 20210049124
    Abstract: The present invention includes an integrated system-on-chip device configured on a substrate member. The device has a data input/output interface provided on the substrate member and configured for a predefined data rate and protocol. The device has an input/output block provided on the substrate member and coupled to the data input/output interface. The input/output block comprises a SerDes block, a CDR block, a compensation block, and an equalizer block. The SerDes block is configured to convert a first data stream of N having a first predefined data rate at a first clock rate into a second data stream of M having a second predefined data rate at a second clock rate. The device has a driver module provided on the substrate member and coupled to a signal processing block, and a driver interface provided on the substrate member and coupled to the driver module and a silicon photonics device.
    Type: Application
    Filed: November 3, 2020
    Publication date: February 18, 2021
    Inventors: Radhakrishnan L. NAGARAJAN, Chao XU
  • Patent number: 10924269
    Abstract: A compact optical transceiver formed by hybrid multichip integration. The optical transceiver includes a Si-photonics chip attached on a PCB. Additionally, the optical transceiver includes a first TSV interposer and a second TSV interposer separately attached nearby the Si-photonics chip on the PCB. Furthermore, the optical transceiver includes a driver chip flip-bonded partially on the Si-photonics chip through a first sets of bumps and partially on the first TSV interposer through a second sets of bumps. Moreover, the optical transceiver includes a transimpedance amplifier module chip flip-bonded partially on the Si-photonics chip through a third sets of bumps and partially on the second TSV interposer through a fourth set of bumps.
    Type: Grant
    Filed: August 2, 2018
    Date of Patent: February 16, 2021
    Assignee: INPHI CORPORATION
    Inventors: Liang Ding, Radhakrishnan L. Nagarajan, Roberto Coccioli
  • Patent number: 10908370
    Abstract: A photonic transceiver apparatus in QSFP package. The apparatus includes a case having a base member, two partial side members, and a lid member to provide a spatial volume with an opening at a back end of the base member. Additionally, the apparatus includes a PCB, installed inside the spatial volume over the base member having a pluggable electrical connector at the back end. Further, the apparatus includes multiple optical transmitting devices in mini-transmit-optical-sub-assembly package, each being mounted on a common support structure and having a laser output port in reversed orientation toward the back end. Furthermore, the apparatus includes a silicon photonics chip, including a fiber-to-silicon attachment module, mounted on the PCB and coupled to a modulation driver module and a trans-impedance amplifier module. Moreover, the apparatus includes a pair of optical input/output ports being back connected to the fiber-to-silicon attachment module.
    Type: Grant
    Filed: February 18, 2020
    Date of Patent: February 2, 2021
    Assignee: INPHI CORPORATION
    Inventors: Radhakrishnan L. Nagarajan, Peng-Chih Li, Masaki Kato
  • Publication number: 20210028860
    Abstract: The present invention is directed to communication systems and methods. According to an embodiment, a receiving optical transceiver determines signal quality for signals received from a transmitting optical transceiver. Information related to the signal quality is embedded into back-channel data and sent to the transmitting optical transceiver. The transmitting optical transceiver detects the presence of the back-channel data and adjusts one or more of its operating parameters based on the back-channel data. There are other embodiments as well.
    Type: Application
    Filed: October 15, 2020
    Publication date: January 28, 2021
    Inventors: Todd ROPE, Radhakrishnan L. NAGARAJAN
  • Patent number: 10892830
    Abstract: An integrated compact light engine configured in a on-board in-package optics assembly. The compact light engine includes a single substrate to integrate multiple optical-electrical modules. Each optical-electrical module includes an integrated optical transceiver based on silicon-photonics platform, in which a transmit path configured to output four light signals centered at four CWDM wavelengths and from four laser devices and to modulate the four light signals respectively by four modulators driven by a driver chip and to deliver a multiplexed transmission light. A receive path includes a photodetector to detect four input signals demultiplexed from an incoming light and a trans-impedance amplifier chip to process electrical signals converted from the four input signals detected. A multi-channel light engine is formed by co-integrating or co-mounting a switch device with multiple compact light engines on a common substrate member to provide up to 51.
    Type: Grant
    Filed: September 25, 2020
    Date of Patent: January 12, 2021
    Assignee: INPHI CORPORATION
    Inventors: Ding Liang, Mark Patterson, Roberto Coccioli, Radhakrishnan L. Nagarajan
  • Patent number: 10892598
    Abstract: A packaged transmitter device includes a base member comprising a planar part mounted with a thermoelectric cooler, a transmitter, and a coupling lens assembly, and an assembling part connected to one side of the planar part. The device further includes a circuit board bended to have a first end region and a second end region being raised to a higher level. The first end region disposed on a top surface of the planar part includes multiple electrical connection patches respectively connected to the thermoelectric and the transmitter. The second end region includes an electrical port for external connection. Additionally, the device includes a cover member disposed over the planar part. Furthermore, the device includes a cylindrical member installed to the assembling part for enclosing an isolator aligned to the coupling lens assembly along its axis and connected to a fiber to couple optical signal from the transmitter to the fiber.
    Type: Grant
    Filed: November 8, 2019
    Date of Patent: January 12, 2021
    Assignees: INPHI CORPORATION, Luxnet Corporation
    Inventors: Radhakrishnan L. Nagarajan, Peng-Chih Li, Pi-Cheng Law
  • Patent number: 10862589
    Abstract: The present invention is directed to communication systems and methods. In a specific embodiment, the present invention provides an optical receiver that receives a data stream from an optical transmitter. The optical receiver determines a histogram contour parameter using the data stream and inserts the histogram contour parameter into a back-channel data segment, which is then transmitted to the optical transmitter. The optical transmitter changes its data transmission setting based on the histogram contour parameter. There are other embodiments as well.
    Type: Grant
    Filed: March 24, 2020
    Date of Patent: December 8, 2020
    Assignee: INPHI CORPORATION
    Inventors: Todd Rope, Hari Shankar, Radhakrishnan L. Nagarajan
  • Patent number: 10860525
    Abstract: The present invention includes an integrated system-on-chip device configured on a substrate member. The device has a data input/output interface provided on the substrate member and configured for a predefined data rate and protocol. The device has an input/output block provided on the substrate member and coupled to the data input/output interface. The input/output block comprises a SerDes block, a CDR block, a compensation block, and an equalizer block. The SerDes block is configured to convert a first data stream of N having a first predefined data rate at a first clock rate into a second data stream of M having a second predefined data rate at a second clock rate. The device has a driver module provided on the substrate member and coupled to a signal processing block, and a driver interface provided on the substrate member and coupled to the driver module and a silicon photonics device.
    Type: Grant
    Filed: April 9, 2020
    Date of Patent: December 8, 2020
    Assignee: INPHI CORPORATION
    Inventors: Radhakrishnan L. Nagarajan, Chao Xu
  • Publication number: 20200379197
    Abstract: A silicon-based edge coupler for coupling a fiber with a waveguide includes a cantilever member being partially suspended with its anchored end coupled to a silicon photonics die in a first part of a silicon substrate and a free end terminated near an edge region separating a second part of the silicon substrate from the first part. The edge coupler further includes a mechanical stopper formed at the edge region with a gap distance ahead of the free end of the cantilever member. Additionally, a V-groove is formed in the second part of the silicon substrate characterized by a top opening and a bottom plane symmetrically connected by two sloped side walls along a fixed Si-crystallography angle. The V-groove is configured to support a fiber with an end facet being pushed against the mechanical stopper and a core center being aligned with the free end of the cantilever member.
    Type: Application
    Filed: August 17, 2020
    Publication date: December 3, 2020
    Inventors: Radhakrishnan L. NAGARAJAN, Masaki KATO
  • Patent number: 10838145
    Abstract: An coherent transceiver includes a single silicon photonics substrate configured to integrate a laser diode chip flip-mounted and coupled with a wavelength tuning section to provide a laser output with tuned wavelengths which is split in X:Y ratio partly into a coherent receiver block as local-oscillator signals and partly into a coherent transmitter block as a light source. The coherent receiver includes a polarization-beam-splitter-rotator to split a coherent input signal to a TE-mode signal and a TM*-mode signal respectively detected by two 90-deg hybrid receivers and a flip-mounted TIA chip assisted by two local-oscillator signals from the tunable laser device.
    Type: Grant
    Filed: April 7, 2020
    Date of Patent: November 17, 2020
    Assignee: INPHI CORPORATION
    Inventor: Radhakrishnan L. Nagarajan
  • Patent number: 10841005
    Abstract: The present invention is directed to communication systems and methods. According to an embodiment, a receiving optical transceiver determines signal quality for signals received from a transmitting optical transceiver. Information related to the signal quality is embedded into back-channel data and sent to the transmitting optical transceiver. The transmitting optical transceiver detects the presence of the back-channel data and adjusts one or more of its operating parameters based on the back-channel data. There are other embodiments as well.
    Type: Grant
    Filed: June 21, 2019
    Date of Patent: November 17, 2020
    Assignee: INPHI CORPORATION
    Inventors: Todd Rope, Radhakrishnan L. Nagarajan
  • Patent number: 10826621
    Abstract: The present invention is directed to a communication signal tracking system comprising an optical receiver including one or more delay line interferometers (DLIs) configured to demultiplex incoming optical signals and a transimpedance amplifier configured to convert the incoming optical signals to incoming electrical signals. The communication signal tracking system further includes a control module configured to calculate a bit-error-rate (BER) of the incoming electrical signals before forward-error correction decoding, and use the BER as a parameter for optimizing settings of the one or more DLIs in one or more iterations in a control loop and generating a back-channel data.
    Type: Grant
    Filed: December 19, 2019
    Date of Patent: November 3, 2020
    Assignee: INPHI CORPORATION
    Inventors: Todd Rope, Sung Choi, James Stewart, Radhakrishnan L. Nagarajan, Paul Yu, Ilya Lyubomirsky
  • Patent number: 10826613
    Abstract: An integrated compact light engine configured in a on-board in-package optics assembly. The compact light engine includes a single substrate to integrate multiple optical-electrical modules. Each optical-electrical module includes an integrated optical transceiver based on silicon-photonics platform, in which a transmit path configured to output four light signals centered at four CWDM wavelengths and from four laser devices and to modulate the four light signals respectively by four modulators driven by a driver chipand to deliver a multiplexed transmission light. A receive path includes a photodetector to detect four input signals demultiplexed from an incoming light and a trans-impedance amplifier chip to process electrical signals converted from the four input signals detected. A multi-channel light engine is formed by co-integrating or co-mounting a switch device with multiple compact light engines on a common substrate member to provide up to 51.
    Type: Grant
    Filed: December 6, 2019
    Date of Patent: November 3, 2020
    Assignee: INPHI CORPORATION
    Inventors: Ding Liang, Mark Patterson, Roberto Coccioli, Radhakrishnan L. Nagarajan