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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Patent number: 11719898Abstract: An assembled electro-optical switch module includes a package substrate. Four optical socket members are disposed respectively to the package substrate. Each optical socket member includes four sockets closely packed in a row. Each socket has a recessed flat region with topside land grid array (LGA) interposer connected to bottom side solder bumps and a side notch opening aligned to an edge of the package substrate at the corresponding edge region. Sixteen optical modules in four sets are co-packaged in the package substrate. Each set has four optical modules respectively seated in the four sockets of each optical socket member with top side LGA interposer. Four clamp latch members are applied to clamp each of the four sets of optical modules in respective optical socket members. A data processor device with 51.2 Tbps data interface is disposed to the package substrate and electrically coupled to each of the sixteen optical modules.Type: GrantFiled: March 3, 2021Date of Patent: August 8, 2023Assignee: Marvell Asia Pte Ltd.Inventors: Radhakrishnan L. Nagarajan, Mark Patterson
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Publication number: 20230225090Abstract: 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: March 16, 2023Publication date: July 13, 2023Inventors: Radhakrishnan L. NAGARAJAN, Liang Ding, Mark Patterson, Roberto Coccioli, Steve Aboagye
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Patent number: 11677478Abstract: A co-packaged optical module includes a substrate, a processor arranged on the substrate and a plurality of light engines mounted around the processor on the substrate using mounting assemblies configured to attach the respective light engines to the substrate. The light engines and the mounting assemblies are disposed along a perimeter of the substrate, including at corners of the substrate. Each of the mounting assemblies includes a socket, a metal clamp clamping a corresponding one of the light engines into the socket, and a plurality of pins which when mated with corresponding holes in the substrate cause peripheries of the mounting assemblies, including the light engines, the sockets and the metal clamps, to be flush with the perimeter of the substrate.Type: GrantFiled: August 10, 2021Date of Patent: June 13, 2023Assignee: MARVELL ASIA PTE LTDInventors: Radhakrishnan L. Nagarajan, Liang Ding, Mark Patterson, Roberto Coccioli, Steve Aboagye
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Patent number: 11664319Abstract: A method for forming a silicon photonics interposer having through-silicon vias (TSVs). The method includes forming vias in a front side of a silicon substrate and defining primary structures for forming optical devices in the front side. Additionally, the method includes bonding a first handle wafer to the front side and thinning down the silicon substrate from the back side and forming bumps at the back side to couple with a conductive material in the vias. Furthermore, the method includes bonding a second handle wafer to the back side and debonding the first handle wafer from the front side to form secondary structures based on the primary structures. Moreover, the method includes forming pads at the front side to couple with the bumps at the back side before completing final structures based on the secondary structures and debonding the second handle wafer from the back side.Type: GrantFiled: June 17, 2022Date of Patent: May 30, 2023Assignee: MARVELL ASIA PTE LTD.Inventors: Liang Ding, Radhakrishnan L. Nagarajan
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Patent number: 11630799Abstract: A hybrid electrical and optic system-on-chip (SOC) device configured for both electrical and optic communication includes a substrate, an electrical device configured for electrical communication arranged on the substrate, a photonics device configured for optic communication arranged on the substrate, and a self-test module arranged on the substrate. The self-test module is configured to receive a loop-back signal indicative of an optical signal output from the photonics device and calibrate the photonics device based on the loop-back signal.Type: GrantFiled: May 23, 2022Date of Patent: April 18, 2023Assignee: Marvell Asia Pte Ltd.Inventors: Radhakrishnan L. Nagarajan, Chao Xu
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Patent number: 11612079Abstract: 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: GrantFiled: August 10, 2021Date of Patent: March 21, 2023Assignee: MARVELL ASIA PTE LTD.Inventors: Radhakrishnan L. Nagarajan, Liang Ding, Mark Patterson, Roberto Coccioli, Steve Aboagye
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Patent number: 11575245Abstract: 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: GrantFiled: February 28, 2020Date of Patent: February 7, 2023Assignee: Marvell Asia Pte Ltd.Inventors: Xiaoguang He, Radhakrishnan L. Nagarajan, Brian Taylor
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Publication number: 20230032160Abstract: An optical module for transmitting data from a data center via a dense wavelength division multiplex (DWDM) grid includes an optical modulator, a multiplexer, and a transmitter. The optical modulator modulates first and second optical signals pulse amplitude modulation for transmission over first and second wavelengths, respectively. The first wavelength is separated from the second wavelength according to a spacing of the DWDM grid for transmitting data at a selected baud rate. The multiplexer multiplexes the modulated first and second optical signals into a multiplexed optical signal, which includes the modulated first optical signal having the first wavelength and the modulated second optical signal having the second wavelength, and outputs the multiplexed optical signal. A transmitter transmits the multiplexed optical signal via the DWDM grid at the selected baud rate.Type: ApplicationFiled: October 14, 2022Publication date: February 2, 2023Inventor: Radhakrishnan L. NAGARAJAN
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Publication number: 20220416900Abstract: An optical transceiver includes a silicon photonics substrate, transmitter circuitry, and receiver circuitry that are heterogeneously integrated. The transmitter circuitry includes a plurality of laser devices formed on the silicon photonics substrate, each of the plurality of laser devices configured to generate a respective laser light, a plurality of modulators formed on the silicon photonics substrate, each of the plurality of modulators configured to modulate the laser lights based on driver signals and output, from the silicon photonics substrate, the modulated laser lights, and a driver formed on the silicon photonics substrate and configured to generate the driver signals.Type: ApplicationFiled: July 5, 2022Publication date: December 29, 2022Inventors: Ding Liang, Mark Patterson, Roberto Coccioli, Radhakrishnan L. Nagarajan
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Publication number: 20220407285Abstract: A photonics device includes a silicon wafer including a cathode region, an anode region, a trench region formed between the cathode region and the anode region, and a linear ridge formed between the cathode region and the anode region. A laser diode chip is mounted on the silicon wafer. A conductor layer disposed between the silicon wafer and the laser diode chip includes a first section disposed between the laser diode chip and the cathode region on a first side of the trench to electrically connect the laser diode chip to a cathode electrode of the photonics device and a second section disposed between the anode region and the laser diode chip on a second side of the trench to electrically connect the laser diode chip to an anode electrode of the photonics device.Type: ApplicationFiled: August 25, 2022Publication date: December 22, 2022Inventors: Xiaoguang HE, Radhakrishnan L. Nagarajan
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Publication number: 20220407604Abstract: A silicon photonics substrate for a transceiver includes a substrate member comprised of a first silicon material, and, heterogeneously formed on the substrate member, receiver circuitry and transmitter circuitry. The receiver circuitry is comprised of a second silicon material and is configured to receive a coherent input signal, generate first and second oscillator signals based on light input from a laser diode, and detect a transverse electric (TE) mode signal and a transverse magnetic (TM) mode signal in the coherent input signal based on the first and second oscillator signals. The transmitter circuitry is comprised of the second or a third silicon material and is configured to transmit signals having the two or more possible modulation formats and modulate the light input from the laser diode in either a TE mode or a TM mode to generate a coherent output signal.Type: ApplicationFiled: July 18, 2022Publication date: December 22, 2022Inventor: Radhakrishnan L. NAGARAJAN
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Publication number: 20220358080Abstract: An optical module configured to control a peer to peer transaction includes a silicon photonics substrate, memory formed on the silicon photonics substrate and configured to store a private key, application circuitry formed on the silicon photonics substrate and coupled to the memory, the application circuitry configured to receive, via an external interface, an electrical signal carrying instructions for executing a transaction, verify the transaction using the private key stored in the memory, and selectively generate a transaction message including information for completing the transaction, and optical communication circuitry formed on the silicon photonics substrate and responsive to the application circuitry, the optical communication circuitry configured to generate an optical signal based on the transaction message and transmit the optical signal to at least one remote entity.Type: ApplicationFiled: July 18, 2022Publication date: November 10, 2022Inventor: Radhakrishnan L. NAGARAJAN
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Patent number: 11483089Abstract: 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: February 5, 2021Date of Patent: October 25, 2022Assignee: MARVELL ASIA PTE LTD.Inventor: Radhakrishnan L. Nagarajan
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Publication number: 20220319994Abstract: A method for forming a silicon photonics interposer having through-silicon vias (TSVs). The method includes forming vias in a front side of a silicon substrate and defining primary structures for forming optical devices in the front side. Additionally, the method includes bonding a first handle wafer to the front side and thinning down the silicon substrate from the back side and forming bumps at the back side to couple with a conductive material in the vias. Furthermore, the method includes bonding a second handle wafer to the back side and debonding the first handle wafer from the front side to form secondary structures based on the primary structures. Moreover, the method includes forming pads at the front side to couple with the bumps at the back side before completing final structures based on the secondary structures and debonding the second handle wafer from the back side.Type: ApplicationFiled: June 17, 2022Publication date: October 6, 2022Inventors: Liang DING, Radhakrishnan L. NAGARAJAN
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Patent number: 11444429Abstract: A photonics device includes a silicon wafer including an upper surface region, a trench region, and a ridge structure. The ridge structure electrically isolates the upper surface region from the trench region. A laser diode chip flip-bonded onto the silicon wafer includes an electrode region bonded with the upper surface region, a gain region bonded with the trench region, and an isolation region bonded with the ridge structure. The isolation region electrically isolates the gain region from the electrode region. A conductor layer arranged between the silicon wafer and the laser diode chip includes a first section electrically connecting the gain region to a first electrode of the photonics device and a second section configured to electrically connect the electrode region to a second electrode of the photonics device. The first section is electrically isolated from the second section by the isolation region.Type: GrantFiled: February 5, 2021Date of Patent: September 13, 2022Assignee: Marvell Asia Pte Ltd.Inventors: Xiaoguang He, Radhakrishnan L. Nagarajan
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Publication number: 20220285906Abstract: A laser device based on silicon photonics with an in-cavity power monitor includes a gain chip mounted on a silicon photonics substrate and configured to emit light in an active region bounded between a frontend facet with low reflectivity and a backend facet with anti-reflective characteristics. The laser device further includes a wavelength tuner formed with waveguides in the silicon photonics substrate optically coupled to the backend facet to receive light from the gain chip and configured to have a reflector with high reflectivity to reflect the light in an extended cavity formed with the frontend facet through which a laser with a tuned wavelength and amplified power is outputted. Additionally, the laser device includes a photodiode formed in the silicon photonics substrate and coupled to the waveguides in the extended cavity right in front of the reflector to measure power of light thereof.Type: ApplicationFiled: March 3, 2021Publication date: September 8, 2022Inventors: Xiaoguang HE, Radhakrishnan L. NAGARAJAN
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Publication number: 20220283982Abstract: A hybrid electrical and optic system-on-chip (SOC) device configured for both electrical and optic communication includes a substrate, an electrical device configured for electrical communication arranged on the substrate, a photonics device configured for optic communication arranged on the substrate, and a self-test module arranged on the substrate. The self-test module is configured to receive a loop-back signal indicative of an optical signal output from the photonics device and calibrate the photonics device based on the loop-back signal.Type: ApplicationFiled: May 23, 2022Publication date: September 8, 2022Inventors: Radhakrishnan L. NAGARAJAN, Chao XU
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Publication number: 20220285913Abstract: 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: May 26, 2022Publication date: September 8, 2022Inventors: Radhakrishnan L. NAGARAJAN, Peng-Chih Li, Pi-Cheng LAW
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Publication number: 20220283360Abstract: An assembled electro-optical switch module includes a package substrate. Four optical socket members are disposed respectively to the package substrate. Each optical socket member includes four sockets closely packed in a row. Each socket has a recessed flat region with topside land grid array (LGA) interposer connected to bottom side solder bumps and a side notch opening aligned to an edge of the package substrate at the corresponding edge region. Sixteen optical modules in four sets are co-packaged in the package substrate. Each set has four optical modules respectively seated in the four sockets of each optical socket member with top side LGA interposer. Four clamp latch members are applied to clamp each of the four sets of optical modules in respective optical socket members. A data processor device with 51.2 Tbps data interface is disposed to the package substrate and electrically coupled to each of the sixteen optical modules.Type: ApplicationFiled: March 3, 2021Publication date: September 8, 2022Inventors: Radhakrishnan L. NAGARAJAN, Mark PATTERSON
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Publication number: 20220263289Abstract: A tunable laser for a transceiver includes a silicon photonics substrate, first and second patterned regions each being defined in the substrate a step lower than a flat surface region of the substrate, first and second laser diode chips arranged in the first and second patterned regions, the patterned regions being configured to align the gain regions of the first and second laser diode chips with integrated couplers formed in the substrate adjacent to the first and second patterned regions to facilitate flip-bonding the first and second laser diode chips within the patterned regions, and a tuning filter coupled to the first laser diode chip and the second laser diode chip via the integrated couplers. The tuning filter is configured to receive laser light from each of the first and second laser diode chips and generate a laser output having a gain determined by each of the gain regions.Type: ApplicationFiled: May 9, 2022Publication date: August 18, 2022Inventors: Radhakrishnan L. NAGARAJAN, Masaki Kato, Nourhan Eid, Kenneth Ling Wong