Patents by Inventor Radhakrishnan Nagarajan

Radhakrishnan 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: 20230336248
    Abstract: An optical module includes a plurality of lasers, each of at least some of the lasers configured to be selectively turned on and turned off depending on a type of modulation to be used. Each laser corresponds to a respective wavelength. The optical module also includes an optical modulation system having a plurality of optical modulators. A reconfigurable optical network of the optical module is configured to selectively direct light from the plurality of lasers to the optical modulation system differently depending on the type of modulation to be used.
    Type: Application
    Filed: April 19, 2023
    Publication date: October 19, 2023
    Inventors: Radhakrishnan NAGARAJAN, Masaki KATO, Gary MAK
  • Publication number: 20230307572
    Abstract: A receiver for receiving optical signals transmitted over a communications network includes a silicon photonics substrate including multiple regions with respectively different doping, an epitaxial germanium layer extending at least partially over at least two or more of regions with different doping, and at least one of a tensile stressor component and a compressive stressor component in contact with the epitaxial germanium layer. The tensile stressor component and the compressive stressor component are respectively configured to mechanically strain the epitaxial germanium layer to modify an optical signal absorption attribute of the epitaxial germanium layer. The receiver includes a receive circuit including at least one electrode component in electrical contact with the epitaxial germanium layer. The receive circuit is configured to generate an electrical output in response to an optical signal received from a network interface of the communications network by the epitaxial germanium layer.
    Type: Application
    Filed: March 24, 2023
    Publication date: September 28, 2023
    Inventors: Liang DING, Masaki Kato, Radhakrishnan Nagarajan
  • Publication number: 20230246417
    Abstract: A tunable laser for generating and outputting wavelength-tuned light using only a single gain chip includes a reflective semiconductor optical amplifier (RSOA) having a front-end configured as an output port for outputting the wavelength-tuned light with an amplified light intensity relative to light received at a back-end of the RSOA. A wavelength tuner is optically coupled to the back-end of the RSOA and includes a plurality of ring resonators having respective Q-factors above 2000 and below 4000.
    Type: Application
    Filed: January 16, 2023
    Publication date: August 3, 2023
    Inventors: Xiaoguang HE, Radhakrishnan Nagarajan
  • Patent number: 9166704
    Abstract: In an example, the present invention includes an integrated system on chip device. The device is configured on a single silicon substrate member. The device has a data input/output interface provided on the substrate member. The device has an input/output block provided on the substrate member and coupled to the data input/output interface. The device has a signal processing block provided on the substrate member and coupled to the input/output block. The device has a driver module provided on the substrate member and coupled to the signal processing block. In an example, the device has a driver interface provided on the substrate member and coupled to the driver module and configured to be coupled to a silicon photonics device. The device also has an interface configured to communicate between the silicon photonics device and the control block.
    Type: Grant
    Filed: July 3, 2014
    Date of Patent: October 20, 2015
    Assignee: Inphi Corporation
    Inventor: Radhakrishnan Nagarajan
  • Publication number: 20080044128
    Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.
    Type: Application
    Filed: June 19, 2007
    Publication date: February 21, 2008
    Applicant: INFINERA CORPORATION
    Inventors: Fred Kish, David Welch, Mark Missey, Radhakrishnan Nagarajan, Atul Mathur, Frank Peters, Richard Schneider, Charles Joyner, Andrew Dentai, Damien Lambert, Masaki Kato, Sheila Hurtt, Randal Salvatore, Mehrdad Ziari, Vincent Dominic
  • Publication number: 20080031626
    Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.
    Type: Application
    Filed: October 9, 2007
    Publication date: February 7, 2008
    Applicant: INFINERA CORPORATION
    Inventors: David Welch, Vincent Dominic, Fred Kish, Mark Missey, Radhakrishnan Nagarajan, Atul Mathur, Frank Peters, Robert Taylor, Matthew Mitchell, Alan Nilsson, Stephen Grubb, Richard Schneider, Charles Joyner, Jonas Webjorn, Ting-Kuang Chiang, Robert Grencavich, Vinh Nguyen, Donald Pavinski, Marco Sosa
  • Publication number: 20080025726
    Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.
    Type: Application
    Filed: June 22, 2007
    Publication date: January 31, 2008
    Applicant: INFINERA CORPORATION
    Inventors: David Welch, Vincent Dominic, Fred Kish, Mark Missey, Radhakrishnan Nagarajan, Atul Mathur, Frank Peters, Richard Schneider, Charles Joyner, Jonas Webjorn, Marco Sosa
  • Publication number: 20080013881
    Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.
    Type: Application
    Filed: July 6, 2007
    Publication date: January 17, 2008
    Applicant: INFINERA CORPORATION
    Inventors: David Welch, Vincent Dominic, Fred Kish, Mark Missey, Radhakrishnan Nagarajan, Atul Mathur, Frank Peters, Robert Taylor, Matthew Mitchell, Alan Nilsson, Stephen Grubb, Richard Schneider, Charles Joyner, Jonas Webjorn, Drew Perkins
  • Publication number: 20070248299
    Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.
    Type: Application
    Filed: June 21, 2007
    Publication date: October 25, 2007
    Applicant: INFINERA CORPORATION
    Inventors: David Welch, Vincent Dominic, Fred Kish, Mark Missey, Radhakrishnan Nagarajan, Atul Mathur, Frank Peters, Robert Taylor, Matthew Mitchell, Alan Nilsson, Stephen Grubb, Richard Schneider, Charles Joyner, Jonas Webjorn, Drew Perkins
  • Publication number: 20070242919
    Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.
    Type: Application
    Filed: June 22, 2007
    Publication date: October 18, 2007
    Applicant: INFINERA CORPORATION
    Inventors: David Welch, Vincent Dominic, Fred Kish, Mark Missey, Radhakrishnan Nagarajan, Atul Mathur, Frank Peters, Robert Taylor, Matthew Mitchell, Alan Nilsson, Stephen Grubb, Richard Schneider, Charles Joyner, Jonas Webjorn, Drew Perkins
  • Publication number: 20070242918
    Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.
    Type: Application
    Filed: June 20, 2007
    Publication date: October 18, 2007
    Applicant: INFINERA CORPORATION
    Inventors: David Welch, Vincent Dominic, Fred Kish, Mark Missey, Radhakrishnan Nagarajan, Atul Mathur, Frank Peters, Robert Taylor, Matthew Mitchell, Alan Nilsson, Stephen Grubb, Richard Schneider, Charles Joyner, Jonas Webjorn, Drew Perkins
  • Publication number: 20070201785
    Abstract: Electro-optic amplitude varying elements (AVEs) or electro-optic multi-function elements (MFEs) are integrated into signal channels of photonic integrated circuits (PICs) or at the output of such PICs to provide for various optical controlling and monitoring functions. In one case, such PIC signal channels may minimally include a laser source and a modulator (TxPIC) and in another case, may minimally include a photodetector to which channels, in either case, an AVE or an MFE may be added.
    Type: Application
    Filed: November 3, 2006
    Publication date: August 30, 2007
    Applicant: INFINERA CORPORATION
    Inventors: David Welch, Fred Kish, Radhakrishnan Nagarajan, Alan Nilsson, Robert Taylor
  • Publication number: 20070183738
    Abstract: Monolithic photonic integrated circuits (PICs) utilize forward error correction (FEC) joint encoder or plural encoders or a joint decoder or plural decoders.
    Type: Application
    Filed: April 14, 2007
    Publication date: August 9, 2007
    Applicant: INFINERA CORPORATION
    Inventors: David Welch, Radhakrishnan Nagarajan, Fred Kish, Mark Missey, Vincent Dominic, Atul Mathur, Frank Peters, Charles Joyner, Richard Schneider, Ting-Kuang Chiang
  • Publication number: 20070127864
    Abstract: Electro-optic amplitude varying elements (AVEs) or electro-optic multi-function elements (MFEs) are integrated into signal channels of photonic integrated circuits (PICs) or at the output of such PICs to provide for various optical controlling and monitoring functions. In one case, such PIC signal channels may minimally include a laser source and a modulator (TxPIC) and in another case, may minimally include a photodetector to which channels, in either case, an AVE or an MFE may be added.
    Type: Application
    Filed: February 3, 2007
    Publication date: June 7, 2007
    Applicant: INFINERA CORPORATION
    Inventors: David Welch, Fred Kish, Radhakrishnan Nagarajan, Alan Nilsson, Robert Taylor
  • Publication number: 20070122148
    Abstract: A method is disclosed for monitoring and controlling the bit error rate (BER) in an optical communication network where an optical receiver in the optical transmission network. The method includes the steps of decombining a combined channel signal received from the network and then monitoring a real time bit error rate (BER) of a decombined channel signal. The determined BER is then communicated, such as through an optical service channel (OSC) to an optical transmitter source that is the source of origin of the channel signal. Based upon the determined BER, the chirp of a channel signal modulator at the optical transmitter source that generated the monitored channel signal is adjusted by, for example, adjusting its bias. The same channel signal received at the optical receiver can be monitored again to determine if an acceptable level for the BER has been achieved by the previous chirp adjustment.
    Type: Application
    Filed: August 9, 2006
    Publication date: May 31, 2007
    Applicant: INFINERA CORPORATION
    Inventors: David Welch, Ting-Kuang Chiang, Vincent Dominic, Fred Kish, Radhakrishnan Nagarajan
  • Publication number: 20060138433
    Abstract: A photonic integrated circuit that includes a plurality of active and passive components on a substrate where one of the components is an optical combiner/decombiner having at least one free space coupler region and a plurality of longitudinal ridge waveguides each extending in the circuit from a first region of the waveguide and coupled at a second region of the waveguide at the free space coupler region. A first dielectric layer formed over the ridge waveguides and the free space coupler region. The first dielectric layer monotonically increases in cross-sectional thickness from the waveguide first region to the second region to reduce signal insertion losses in transitioning from the ridge waveguides to the free space coupler region. The first dielectric layer may be covered with a second passivation layer. The first dielectric layer may be SiOx, SiNx or SixONy and the second passivation layer may be BCB, ZnS or ZnSe.
    Type: Application
    Filed: February 21, 2006
    Publication date: June 29, 2006
    Applicant: Infinera Corporation
    Inventors: Charles Joyner, Mark Missey, Radhakrishnan Nagarajan, Fred Kish
  • Publication number: 20060140574
    Abstract: Cleaved grooves, also referred to herein as “cleave streets”, are formed exclusively in a wafer passivation layer overlaying a wafer to provide for correctly aligned and sharp cleaves prior to singulation of the wafer into separate die or chips.
    Type: Application
    Filed: February 27, 2006
    Publication date: June 29, 2006
    Applicant: Infinera Corporation
    Inventors: Charles Joyner, Mark Missey, Radhakrishnan Nagarajan, Frank Peters, Mehradad Ziari, Fred Kish
  • Publication number: 20060141649
    Abstract: A method for reducing insertion loss in a transition region between a plurality of input or output waveguides to a free space coupler region in a photonic integrated circuit (PIC) includes the steps of forming a passivation layer over the waveguides and region and forming the passivation overlayer such that it monotonically increases in thickness through the transition region to the free space coupler region.
    Type: Application
    Filed: February 21, 2006
    Publication date: June 29, 2006
    Applicant: Infinera Corporation
    Inventors: Charles Joyner, Mark Missey, Radhakrishnan Nagarajan, Fred Kish
  • Publication number: 20060133717
    Abstract: Disclosed is a method of adjusting a center channel wavelength of a group of channel wavelengths from of a plurality of modulated sources, integrated in a photonic integrated circuit (PIC), relative to the center of a wavelength passband of an optical combiner, such as an arrayed waveguide array (AWG), also integrated in the photonic integrated circuit (PIC) and optically coupled to outputs from the modulated sources.
    Type: Application
    Filed: December 17, 2004
    Publication date: June 22, 2006
    Applicant: Infinera Corporation
    Inventors: Charles Joyner, Mark Missey, Radhakrishnan Nagarajan, Fred Kish
  • Publication number: 20060093362
    Abstract: Electro-optic amplitude varying elements (AVEs) or electro-optic multi-function elements (MFEs) are integrated into signal channels of photonic integrated circuits (PICs) or at the output of such PICs to provide for various optical controlling and monitoring functions. In one case, such PIC signal channels may minimally include a laser source and a modulator (TxPIC) and in another case, may minimally include a photodetector to which channels, in either case, an AVE or an MFE may be added.
    Type: Application
    Filed: November 7, 2005
    Publication date: May 4, 2006
    Applicant: Infinera Corporation
    Inventors: David Welch, Fred Kish, Radhakrishnan Nagarajan, Alan Nilsson, Robert Taylor