Patents by Inventor Sumesh Mani K. Thiyagarajan

Sumesh Mani K. Thiyagarajan 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: 9157949
    Abstract: A method of accelerating the aging of a laser to thereby determine the reliability of the laser. The method includes an act of providing a laser die for reliability testing, an act of applying a plurality of short signal pulses to the laser die so as to simulate the aging of the laser die, and an act of ascertaining the reliability of the laser die based on its response to the plurality of short signal pulses.
    Type: Grant
    Filed: October 22, 2012
    Date of Patent: October 13, 2015
    Assignee: FINISAR CORPORATION
    Inventor: Sumesh Mani K. Thiyagarajan
  • Patent number: 8705582
    Abstract: In one example embodiment, a DFB laser includes a substrate; an active region positioned above the substrate; a grating layer positioned above the active region, the grating layer including a portion that serves as a primary etch stop layer; a secondary etch stop layer positioned above the grating layer; and a spacer layer interposed between the grating layer and the secondary etch stop layer.
    Type: Grant
    Filed: July 1, 2013
    Date of Patent: April 22, 2014
    Assignee: Finisar Corporation
    Inventors: Ashish K. Verma, Tsurugi Sudo, Sumesh Mani K. Thiyagarajan, David Bruce Young
  • Publication number: 20130287405
    Abstract: In one example embodiment, a DFB laser includes a substrate; an active region positioned above the substrate; a grating layer positioned above the active region, the grating layer including a portion that serves as a primary etch stop layer; a secondary etch stop layer positioned above the grating layer; and a spacer layer interposed between the grating layer and the secondary etch stop layer.
    Type: Application
    Filed: July 1, 2013
    Publication date: October 31, 2013
    Inventors: Ashish K. Verma, Tsurugi Sudo, Sumesh Mani K. Thiyagarajan, David Bruce Young
  • Patent number: 8477817
    Abstract: In one example embodiment, a DFB laser includes a substrate, an active region positioned above the substrate, and a grating layer positioned above the active region. The grating layer includes a portion that serves as a primary etch stop layer. The DFB laser also includes a secondary etch stop layer located either above or below the grating layer, and a spacer layer interposed between the grating layer and the active region.
    Type: Grant
    Filed: October 11, 2010
    Date of Patent: July 2, 2013
    Assignee: Finisar Corporation
    Inventors: Ashish K. Verma, Tsurugi Sudo, Sumesh Mani K. Thiyagarajan, David Bruce Young
  • Patent number: 8294484
    Abstract: A method of accelerating the aging of a laser to thereby determine the reliability of the laser. The method includes an act of providing a laser die for reliability testing, an act of applying a plurality of short signal pulses to the laser die so as to simulate the aging of the laser die, and an act of ascertaining the reliability of the laser die based on its response to the plurality of short signal pulses.
    Type: Grant
    Filed: May 30, 2008
    Date of Patent: October 23, 2012
    Assignee: Finisar Corporation
    Inventor: Sumesh Mani K. Thiyagarajan
  • Patent number: 8085824
    Abstract: One example disclosed herein relates to a method of at least partially optimizing one or more output performance parameters of a laser die. The method includes an act of identifying one or more output performance parameters to be at least partially optimized, an act of identifying one or more design parameters associated with the one or more output performance parameters, an act of determining a subset of the one or more design parameters that should be varied so as to at least partially effect the one or more output performance parameters, an act of varying the subset of design parameters to produce one or more intermediate results, and an act of using the intermediate results to determine values for the one or more design parameters such that the one or more performance parameters are at least partially optimized.
    Type: Grant
    Filed: May 29, 2008
    Date of Patent: December 27, 2011
    Assignee: Finisar Corporation
    Inventors: Sumesh Mani K. Thiyagarajan, Ashish K. Verma
  • Patent number: 7848375
    Abstract: Embodiments disclosed herein relate to a laser die. The laser die includes a base epitaxial portion, a mesa portion, and first and second facets, wherein at least one of the first and second facets is flared such that an area of the facet is increased. Embodiments disclosed herein also relate to a high-speed laser. The high-speed laser includes a substrate, an active region positioned above the substrate, a mesa positioned above the active region, and one or more facets, wherein at least one of the one or more facets includes a flared portion configured to increase an area of the facet.
    Type: Grant
    Filed: May 30, 2008
    Date of Patent: December 7, 2010
    Assignee: Finisar Corporation
    Inventor: Sumesh Mani K. Thiyagarajan
  • Patent number: 7813395
    Abstract: In one example embodiment, a DFB laser includes a substrate, an active region positioned above the substrate, and a grating layer positioned above the active region. The grating layer includes a portion that serves as a primary etch stop layer. The DFB laser also includes a secondary etch stop layer located either above or below the grating layer, and a spacer layer interposed between the grating layer and the active region.
    Type: Grant
    Filed: June 12, 2008
    Date of Patent: October 12, 2010
    Assignee: Finisar Corporation
    Inventors: Ashish K. Verma, Tsurugi Sudo, Sumesh Mani K. Thiyagarajan, David Bruce Young
  • Patent number: 7606279
    Abstract: Embodiments disclosed herein relate to high-speed lasers such as FP and DFB lasers. In one embodiment, the high speed laser comprises a substrate, an active region positioned above the substrate, a mesa positioned above the active region, and one or more layers disposed between the active region and the mesa, wherein the thickness of at least one of the one or more layers is implemented to at least partially minimize the distance between the mesa and active region such that lateral current spreading between the mesa and the active region is at least partially minimized.
    Type: Grant
    Filed: May 15, 2007
    Date of Patent: October 20, 2009
    Assignee: Finisar Corporation
    Inventors: Ashish K. Verma, Sumesh Mani K. Thiyagarajan, David Bruce Young, Yuk Lung Ha, Roman Dimitrov
  • Patent number: 7567601
    Abstract: A laser diode having a composite passivation layer configured to control parasitic capacitance, especially in high speed laser applications, is disclosed. In one embodiment, a ridge waveguide laser is disclosed and includes: a substrate, an active layer disposed on the substrate, a ridge structure disposed on the active layer, and a contact layer disposed on the ridge structure. A composite passivation layer is disposed substantially laterally to the ridge structure. The composite passivation layer includes a silicon nitride bottom layer, a silicon nitride top layer, and a silicon dioxide middle layer interposed between the bottom and top layers. The passivation layers possess differing stress components that, when combined, cancel out the overall mechanical stress of the passivation layer. This enables relatively thick passivation layers to be employed in high speed laser diodes without increasing the risk of layer stress cracking and laser damage.
    Type: Grant
    Filed: May 15, 2007
    Date of Patent: July 28, 2009
    Assignee: Finisar Corporation
    Inventors: Tsurugi Sudo, Ashish Verma, Jing Chai, Sumesh Mani K. Thiyagarajan
  • Publication number: 20080301595
    Abstract: One example disclosed herein relates to a method of at least partially optimizing one or more output performance parameters of a laser die.
    Type: Application
    Filed: May 29, 2008
    Publication date: December 4, 2008
    Applicant: FINISAR CORPORATION
    Inventors: Sumesh Mani K. Thiyagarajan, Ashish K. Verma
  • Patent number: 6878565
    Abstract: A distributed feedback (DFB) laser is constructed such that a laser stripe has a minimum tilt angle with respect to a cleaved facet in order to reduce the facet reflectivity. A method for improving the yield of distributed feedback lasers is also provided. The method includes selecting a tilt angle and antireflection coating to achieve a desired effective facet reflectivity. In one embodiment, a range of tilt angles and facet coatings is tested to determine a statistical correlation between yield of a desired laser characteristic, such as side mode suppression ratio, and tilt angle.
    Type: Grant
    Filed: October 27, 2003
    Date of Patent: April 12, 2005
    Assignee: Finisar Corporation
    Inventor: Sumesh Mani K. Thiyagarajan
  • Publication number: 20040131099
    Abstract: A distributed feedback (DFB) laser is constructed such that a laser stripe has a minimum tilt angle with respect to a cleaved facet in order to reduce the facet reflectivity. A method for improving the yield of distributed feedback lasers is also provided. The method includes selecting a tilt angle and antireflection coating to achieve a desired effective facet reflectivity. In one embodiment, a range of tilt angles and facet coatings is tested to determine a statistical correlation between yield of a desired laser characteristic, such as side mode suppression ratio, and tilt angle.
    Type: Application
    Filed: October 27, 2003
    Publication date: July 8, 2004
    Applicant: Finisar Corporation
    Inventor: Sumesh Mani K. Thiyagarajan