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).
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Publication number: 20210385975Abstract: An optical communication system includes a co-packaged optical module and a heatsink mounted to the co-packaged optical module. The co-packaged optical module includes a processor disposed on a substrate and a plurality of light engines disposed at different locations around the processor on the substrate. The processor and the light engines generating different amounts of heat during operation. The heatsink includes a plurality of heat pipes non-uniformly distributed throughout the heatsink to remove the different amounts of heat generated at a location of the processor and respective locations of the different ones of the light engines.Type: ApplicationFiled: August 10, 2021Publication date: December 9, 2021Inventors: Radhakrishnan L. NAGARAJAN, Liang DING, Mark PATTERSON, Roberto COCCIOLI, Steve ABOAGYE
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Publication number: 20210385560Abstract: A co-packaged optical-electrical module includes a module substrate with a minimum lateral dimension no greater than 100 mm. The co-packaged optical-electrical module further includes a main die with a processor chip disposed at a central region of the module substrate, the processor chip being configured to operate with a digital-signal processing (DSP) interface for extra-short-reach data interconnect. Additionally, the co-packaged optical-electrical module includes a plurality of chiplet dies disposed densely along a peripheral region of the module substrate. Each chiplet die is configured to be self-packaged light engine on a sub-module substrate with a minimum lateral dimension to allow a maximum number of chiplet dies on the module substrate with a distance of any chiplet die from the main die smaller than 50 mm for extra-short-reach interconnect operation.Type: ApplicationFiled: June 5, 2020Publication date: December 9, 2021Inventors: Radhakrishnan L. NAGARAJAN, Liang DING, Mark PATTERSON, Roberto COCCIOLI, Steve ABOAGYE
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Patent number: 11178473Abstract: A co-packaged optical-electrical module includes a module substrate with a minimum lateral dimension no greater than 100 mm. The co-packaged optical-electrical module further includes a main die with a processor chip disposed at a central region of the module substrate, the processor chip being configured to operate with a digital-signal processing (DSP) interface for extra-short-reach data interconnect. Additionally, the co-packaged optical-electrical module includes a plurality of chiplet dies disposed densely along a peripheral region of the module substrate. Each chiplet die is configured to be self-packaged light engine on a sub-module substrate with a minimum lateral dimension to allow a maximum number of chiplet dies on the module substrate with a distance of any chiplet die from the main die smaller than 50 mm for extra-short-reach interconnect operation.Type: GrantFiled: June 5, 2020Date of Patent: November 16, 2021Assignee: MARVELL ASIA PTE, LTD.Inventors: Radhakrishnan L. Nagarajan, Liang Ding, Mark Patterson, Roberto Coccioli, Steve Aboagye
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Patent number: 11165509Abstract: A method for co-packaging multiple light engines in a switch module is provided. The method includes providing a module substrate with a minimum lateral dimension no greater than 110 mm. The module substrate is configured with a first mounting site at a center region and a plurality of second mounting sites distributed densely along the peripheral sides. The method includes disposing a main die with a switch processor chip at the first mounting site. The switch processor chip is configured to operate with a digital-signal processing (DSP) interface for extra-short-reach data interconnect. The method further includes mounting a plurality of chiplet dies respectively into the plurality of second mounting sites. Each chiplet die is configured to be a packaged light engine with a minimum lateral dimension to allow a maximum number of chiplet dies with <50 mm from the main die for extra-short-reach data interconnect.Type: GrantFiled: June 5, 2020Date of Patent: November 2, 2021Assignee: MARVELL ASIA PTE, LTD.Inventors: Radhakrishnan L. Nagarajan, Liang Ding, Mark Patterson, Roberto Coccioli, Steve Aboagye
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Patent number: 11153013Abstract: 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: GrantFiled: November 5, 2020Date of Patent: October 19, 2021Assignee: MARVELL ASIA PTE, LTD.Inventors: Todd Rope, Hari Shankar, Radhakrishnan L. Nagarajan
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Publication number: 20210273408Abstract: A thin-film device for a wavelength-tunable semiconductor laser. The device includes a cavity between a high-reflectivity facet and an anti-reflection facet designed to emit a laser light of a wavelength in a tunable range determined by two Vernier-ring resonators with a joint-free-spectral-range between a first wavelength and a second wavelength. The device further includes a film including multiple pairs of a first layer and a second layer sequentially stacking to an outer side of the high-reflectivity facet. Each layer in each pair has one unit of respective optical thickness except one first or second layer in one pair having a larger optical thickness. The film is configured to produce inner reflectivity of the laser light from the high-reflectivity facet at least >90% for wavelengths in the tunable range starting from the first wavelength but at least <50% for wavelengths in a 25 nm range around the second wavelength.Type: ApplicationFiled: February 28, 2020Publication date: September 2, 2021Inventors: Xiaoguang HE, Radhakrishnan L. NAGARAJAN, Brian TAYLOR
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Patent number: 11109515Abstract: An integrated heatsink for a co-packaged optical-electrical module includes a base plate attached on top of a co-packaged optical-electrical module. The integrated heatsink further includes a plurality of fin structures extended upward from the base plate except a central cavity region with missing sections of fins, each fin extended along an axial direction from a front edge to a back edge of the base plate except some trenches shallow in depth across some fin structures and some other trenches deep in depth down to the base plate either along or across some fin structures. Additionally, the integrated heatsink includes multiple heat pipes including shaped portions embedded in the trenches in the plurality of fin structures. At least one bottom horizontal portion per heat pipe is brazed to the base plate in a corresponding region that is superimposed on hot spots of the co-packaged optical-electrical module under the base plate.Type: GrantFiled: June 5, 2020Date of Patent: August 31, 2021Assignee: INPHI CORPORATIONInventors: Radhakrishnan L. Nagarajan, Liang Ding, Mark Patterson, Roberto Coccioli, Steve Aboagye
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Publication number: 20210265805Abstract: 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: ApplicationFiled: February 5, 2021Publication date: August 26, 2021Inventors: Xiaoguang HE, Radhakrishnan L. NAGARAJAN
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Publication number: 20210175973Abstract: 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: ApplicationFiled: December 9, 2020Publication date: June 10, 2021Inventors: Ding LIANG, Mark PATTERSON, Roberto COCCIOLI, Radhakrishnan L. NAGARAJAN
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Publication number: 20210159997Abstract: 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: ApplicationFiled: February 5, 2021Publication date: May 27, 2021Inventor: Radhakrishnan L. NAGARAJAN
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Patent number: 11002913Abstract: An optical dispersion compensator integrated with a silicon photonics system including a first phase-shifter coupled to a second phase-shifter in parallel on the silicon substrate characterized in an athermal condition. The dispersion compensator further includes a third phase-shifter on the silicon substrate to the first phase-shifter and the second phase-shifter through two 2×2 splitters to form an optical loop. A second entry port of a first 2×2 splitter is for coupling with an input fiber and a second exit port of a second 2×2 splitter is for coupling with an output fiber. The optical loop is characterized by a total phase delay tunable via each of the first phase-shifter, the second phase-shifter, and the third phase-shifter such that a normal dispersion (>0) at a certain wavelength in the input fiber is substantially compensated and independent of temperature.Type: GrantFiled: March 30, 2020Date of Patent: May 11, 2021Assignee: INPHI CORPORATIONInventors: Xiaoguang Tu, Radhakrishnan L. Nagarajan, Masaki Kato
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Patent number: 10989937Abstract: An integrated differential Electro-Absorption Modulator (EAM) device. The device includes a substrate, an electrical driver, and two EAM modules. The electrical driver circuit is configured overlying the substrate member and has one output electrically coupled to the first EAM module and the other output electrically coupled to the second EAM module. The first and second EAM modules have a first and a second output, respectively. A beam splitter can be configured to split an optical input into two optical outputs, each of which can be optically coupled to the optical inputs of the first and second EAM modules.Type: GrantFiled: July 2, 2018Date of Patent: April 27, 2021Assignee: INPHI CORPORATIONInventor: Radhakrishnan L. Nagarajan
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Publication number: 20210088738Abstract: 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: ApplicationFiled: September 20, 2019Publication date: March 25, 2021Inventors: Chris TOGAMI, Radhakrishnan L. NAGARAJAN, Gary SASSER, Brian TAYLOR
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Publication number: 20210091536Abstract: 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: ApplicationFiled: December 8, 2020Publication date: March 25, 2021Inventors: Radhakrishnan L. NAGARAJAN, Peng-Chih LI, Pi-Cheng LAW
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Publication number: 20210088739Abstract: 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: ApplicationFiled: November 11, 2020Publication date: March 25, 2021Inventors: Chris TOGAMI, Radhakrishnan L. NAGARAJAN, Gary SASSER, Brian TAYLOR
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Patent number: 10951003Abstract: 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: GrantFiled: February 25, 2020Date of Patent: March 16, 2021Assignee: INPHI CORPORATIONInventors: Xiaoguang He, Radhakrishnan L. Nagarajan
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Patent number: 10951343Abstract: 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: GrantFiled: July 10, 2020Date of Patent: March 16, 2021Assignee: INPHI CORPORATIONInventor: Radhakrishnan L. Nagarajan
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Patent number: 10942323Abstract: 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: GrantFiled: September 20, 2019Date of Patent: March 9, 2021Assignee: INPHI CORPORATIONInventors: Chris Togami, Radhakrishnan L. Nagarajan, Gary Sasser, Brian Taylor
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Publication number: 20210058160Abstract: 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: ApplicationFiled: November 5, 2020Publication date: February 25, 2021Inventors: Todd ROPE, Hari SHANKAR, Radhakrishnan L. NAGARAJAN
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Patent number: D933617Type: GrantFiled: September 13, 2019Date of Patent: October 19, 2021Assignee: MARVELL ASIA PTE, LTD.Inventors: Chris Togami, Radhakrishnan L. Nagarajan, Gary Sasser, Brian Taylor