Patents by Inventor Stevan S. Djordjevic

Stevan S. Djordjevic 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: 20190187373
    Abstract: In some embodiments, an integrated photonic module contains, a silicon-on-insulator platform, an integrated photonic component, and an optical fiber. The silicon-on-insulator platform can contain a silicon-on-insulator photonic circuit, a co-fabricated spot size converter, and a co-fabricated micromachined trench structure. The co-fabricated micromachined trench structure can contain dimensions compatible with the optical fiber, and the optical fiber can be bonded to, and disposed at least partially within, the micromachined trench structure. The optical modes of the optical fiber, the integrated photonic component, the co-fabricated spot size converter, and the silicon-on-insulator photonic circuit can also be spatially aligned with one another.
    Type: Application
    Filed: December 12, 2018
    Publication date: June 20, 2019
    Applicant: Roshmere, Inc.
    Inventors: Ivan Shubin, Stevan S. Djordjevic, Ping-Piu Kuo
  • Patent number: 10222552
    Abstract: An integrated circuit is described. This integrated circuit includes an optical waveguide defined in a semiconductor layer, and a dielectric optical waveguide disposed on the semiconductor layer and that overlaps a region of the optical waveguide. Moreover, the dielectric optical waveguide includes an optical device (such as a mirror) on a facet separating a first portion of the dielectric optical waveguide and a second portion of the dielectric optical waveguide. The facet may be at an angle relative to a plane of the dielectric optical waveguide and may include a metal layer. During operation, an optical signal conveyed by the optical waveguide is evanescent coupled to the dielectric optical waveguide. Then, the optical signal may be reflected by the optical device. For example, the angle of the facet may be 45°, so that the optical signal is reflected normal to the plane of the dielectric optical waveguide.
    Type: Grant
    Filed: January 12, 2016
    Date of Patent: March 5, 2019
    Assignee: Oracle International Corporation
    Inventors: Stevan S. Djordjevic, Xuezhe Zheng, Ashok V. Krishnamoorthy
  • Publication number: 20180083420
    Abstract: A laser includes a reflective gain medium (RGM) comprising an optical gain material coupled with an associated reflector. The RGM is coupled to a spot-size converter (SSC), which optically couples the RGM to an optical reflector through a silicon waveguide. The SSC converts an optical mode-field size of the RGM to an optical mode-field size of the silicon waveguide. A negative thermo-optic coefficient (NTOC) waveguide is fabricated on top of the SSC. In this way, an optical signal, which originates from the RGM, passes into the SSC, is coupled into the NTOC waveguide, passes through the NTOC waveguide, and is coupled back into the SSC before passing into the silicon waveguide. During operation, the RGM, the spot-size converter, the NTOC waveguide, the silicon waveguide and the silicon mirror collectively form a lasing cavity for the athermal laser. Finally, a laser output is optically coupled to the lasing cavity.
    Type: Application
    Filed: January 12, 2017
    Publication date: March 22, 2018
    Applicant: Oracle International Corporation
    Inventors: Jock T. Bovington, Stevan S. Djordjevic, Xuezhe Zheng, Ashok V. Krishnamoorthy
  • Patent number: 9923335
    Abstract: A laser includes a reflective gain medium (RGM) comprising an optical gain material coupled with an associated reflector. The RGM is coupled to a spot-size converter (SSC), which optically couples the RGM to an optical reflector through a silicon waveguide. The SSC converts an optical mode-field size of the RGM to an optical mode-field size of the silicon waveguide. A negative thermo-optic coefficient (NTOC) waveguide is fabricated on top of the SSC. In this way, an optical signal, which originates from the RGM, passes into the SSC, is coupled into the NTOC waveguide, passes through the NTOC waveguide, and is coupled back into the SSC before passing into the silicon waveguide. During operation, the RGM, the spot-size converter, the NTOC waveguide, the silicon waveguide and the silicon mirror collectively form a lasing cavity for the athermal laser. Finally, a laser output is optically coupled to the lasing cavity.
    Type: Grant
    Filed: January 12, 2017
    Date of Patent: March 20, 2018
    Assignee: Oracle International Corporation
    Inventors: Jock T. Bovington, Stevan S. Djordjevic, Xuezhe Zheng, Ashok V. Krishnamoorthy
  • Publication number: 20170199327
    Abstract: An integrated circuit is described. This integrated circuit includes an optical waveguide defined in a semiconductor layer, and a dielectric optical waveguide disposed on the semiconductor layer and that overlaps a region of the optical waveguide. Moreover, the dielectric optical waveguide includes an optical device (such as a mirror) on a facet separating a first portion of the dielectric optical waveguide and a second portion of the dielectric optical waveguide. The facet may be at an angle relative to a plane of the dielectric optical waveguide and may include a metal layer. During operation, an optical signal conveyed by the optical waveguide is evanescent coupled to the dielectric optical waveguide. Then, the optical signal may be reflected by the optical device. For example, the angle of the facet may be 45°, so that the optical signal is reflected normal to the plane of the dielectric optical waveguide.
    Type: Application
    Filed: January 12, 2016
    Publication date: July 13, 2017
    Applicant: Oracle International Corporation
    Inventors: Stevan S. Djordjevic, Xuezhe Zheng, Ashok V. Krishnamoorthy
  • Patent number: 9470914
    Abstract: An electro-refraction modulator includes a series of layers with different doping levels surrounding a single-crystal regrown p-n junction implemented in a silicon-on-insulator (SOI) technology. The regrown p-n junction is spatially abrupt and precisely defined, which significantly increases the tuning efficiency of the electro-refraction modulator while maintaining acceptable insertion loss. Consequently, the electro-refraction modulator (such as a resonator modulator or a Mach-Zehnder interferometer modulator) can have high bandwidth, compact size and reduced drive voltage. The improved performance of the electro-refraction modulator may facilitate silicon-photonic links for use in applications such as wavelength-division multiplexing.
    Type: Grant
    Filed: July 23, 2015
    Date of Patent: October 18, 2016
    Assignee: ORACLE INTERNATIONAL CORPORATION
    Inventors: Stevan S. Djordjevic, John E. Cunningham, Ashok V. Krishnamoorthy
  • Patent number: 9465169
    Abstract: An optical device is described. This optical device includes optical components having resonance wavelengths that match target values with a predefined accuracy (such as 0.1 nm) and with a predefined time stability (such as permanent or an infinite time stability) without thermal tuning and/or electronic tuning. The stable, accurate resonance wavelengths may be achieved using a wafer-scale, single (sub-second) shot trimming technique that permanently corrects the phase errors induced by material variations and fabrication inaccuracies in the optical components (and, more generally, resonant silicon-photonic optical components). In particular, the trimming technique may use photolithographic exposure of the optical components on the wafer in parallel, with time-modulation for each individual optical component based on active-element control.
    Type: Grant
    Filed: February 18, 2015
    Date of Patent: October 11, 2016
    Assignee: ORACLE INTERNATIONAL CORPORATION
    Inventors: Stevan S. Djordjevic, Shiyun Lin, Ivan Shubin, Xuezhe Zheng, John E. Cunningham, Ashok V. Krishnamoorthy
  • Publication number: 20160238791
    Abstract: An optical device is described. This optical device includes optical components having resonance wavelengths that match target values with a predefined accuracy (such as 0.1 nm) and with a predefined time stability (such as permanent or an infinite time stability) without thermal tuning and/or electronic tuning. The stable, accurate resonance wavelengths may be achieved using a wafer-scale, single (sub-second) shot trimming technique that permanently corrects the phase errors induced by material variations and fabrication inaccuracies in the optical components (and, more generally, resonant silicon-photonic optical components). In particular, the trimming technique may use photolithographic exposure of the optical components on the wafer in parallel, with time-modulation for each individual optical component based on active-element control.
    Type: Application
    Filed: February 18, 2015
    Publication date: August 18, 2016
    Applicant: Oracle International Corporation
    Inventors: Stevan S. Djordjevic, Shiyun Lin, Ivan Shubin, Xuezhe Zheng, John E. Cunningham, Ashok V. Krishnamoorthy
  • Patent number: 9411177
    Abstract: An integrated optical device includes an electro-absorption modulator disposed on a top surface of an optical waveguide. The electro-absorption modulator includes germanium disposed in a cavity between an n-type doped silicon sidewall and a p-type doped silicon sidewall. By applying a voltage between the n-type doped silicon sidewall and the p-type doped silicon sidewall, an electric field can be generated in a plane of the optical waveguide, but perpendicular to a propagation direction of the optical signal. This electric field shifts a band gap of the germanium, thereby modulating the optical signal.
    Type: Grant
    Filed: June 17, 2015
    Date of Patent: August 9, 2016
    Assignee: ORACLE INTERNATIONAL CORPORATION
    Inventors: John E. Cunningham, Jin Yao, Ivan Shubin, Guoliang Li, Xuezhe Zheng, Shiyun Lin, Hiren D. Thacker, Stevan S. Djordjevic, Ashok V. Krishnamoorthy
  • Patent number: 9373934
    Abstract: A hybrid optical source includes a substrate with an optical amplifier (such as a III-V semiconductor optical amplifier). The substrate is coupled at an angle (such as an angle between 0 and 90°) to a silicon-on-insulator chip. In particular, the substrate may be optically coupled to the silicon-on-insulator chip by an optical coupler (such as a diffraction grating or a mirror) that efficiently couples (i.e., with low optical loss) an optical signal into a sub-micron silicon-on-insulator optical waveguide. Moreover, the silicon-on-insulator optical waveguide optically couples the light to a reflector to complete the hybrid optical source.
    Type: Grant
    Filed: January 27, 2014
    Date of Patent: June 21, 2016
    Assignee: ORACLE INTERNATIONAL CORPORATION
    Inventors: Shiyun Lin, Stevan S. Djordjevic, John E. Cunningham, Xuezhe Zheng, Ashok V. Krishnamoorthy
  • Patent number: 9257814
    Abstract: A hybrid optical source that provides an optical signal having a wavelength is described. This hybrid optical source comprises an optical amplifier (such as a III-V semiconductor optical amplifier) that is butt-coupled or vertically coupled to a silicon-on-insulator (SOI) platform, and which outputs an optical signal. The SOI platform comprises an optical waveguide that conveys the optical signal. A temperature-compensation element included in the optical waveguide compensates for temperature dependence of the indexes of refraction of the optical amplifier and the optical waveguide. In addition, a reflector, included in or in-line with the optical waveguide and after the temperature-compensation element, reflects a portion of the optical signal and transmits another portion of the optical signal that has the wavelength.
    Type: Grant
    Filed: December 11, 2014
    Date of Patent: February 9, 2016
    Assignee: ORACLE INTERNATIONAL CORPORATION
    Inventors: Stevan S. Djordjevic, Xuezhe Zheng, Jin Yao, John E. Cunningham, Kannan Raj, Ashok V. Krishnamoorthy
  • Publication number: 20150362764
    Abstract: An integrated optical device includes an electro-absorption modulator disposed on a top surface of an optical waveguide. The electro-absorption modulator includes germanium disposed in a cavity between an n-type doped silicon sidewall and a p-type doped silicon sidewall. By applying a voltage between the n-type doped silicon sidewall and the p-type doped silicon sidewall, an electric field can be generated in a plane of the optical waveguide, but perpendicular to a propagation direction of the optical signal. This electric field shifts a band gap of the germanium, thereby modulating the optical signal.
    Type: Application
    Filed: June 17, 2015
    Publication date: December 17, 2015
    Inventors: John E. Cunningham, Jin Yao, Ivan Shubin, Guoliang Li, Xuezhe Zheng, Shiyun Lin, Hiren D. Thacker, Stevan S. Djordjevic, Ashok V. Krishnamoorthy
  • Publication number: 20150293383
    Abstract: An integrated optical device includes an electro-absorption modulator disposed on a top surface of an optical waveguide. The electro-absorption modulator includes germanium disposed in a cavity between an n-type doped silicon sidewall and a p-type doped silicon sidewall. By applying a voltage between the n-type doped silicon sidewall and the p-type doped silicon sidewall, an electric field can be generated in a plane of the optical waveguide, but perpendicular to a propagation direction of the optical signal. This electric field shifts a band gap of the germanium, thereby modulating the optical signal.
    Type: Application
    Filed: April 14, 2014
    Publication date: October 15, 2015
    Applicant: Oracle International Corporation
    Inventors: John E. Cunningham, Jin Yao, Ivan Shubin, Guoliang Li, Xuezhe Zheng, Shiyun Lin, Hiren D. Thacker, Stevan S. Djordjevic, Ashok V. Krishnamoorthy
  • Publication number: 20150280403
    Abstract: A hybrid optical source includes a substrate with an optical amplifier (such as a III-V semiconductor optical amplifier). The substrate is coupled at an angle (such as an angle between 0 and 90°) to a silicon-on-insulator chip. In particular, the substrate may be optically coupled to the silicon-on-insulator chip by an optical coupler (such as a diffraction grating or a mirror) that efficiently couples (i.e., with low optical loss) an optical signal into a sub-micron silicon-on-insulator optical waveguide. Moreover, the silicon-on-insulator optical waveguide optically couples the light to a reflector to complete the hybrid optical source.
    Type: Application
    Filed: January 27, 2014
    Publication date: October 1, 2015
    Applicant: Oracle International Corporation
    Inventors: Shiyun Lin, Stevan S. Djordjevic, John E. Cunningham, Xuezhe Zheng, Ashok V. Krishnamoorthy
  • Patent number: 9142698
    Abstract: An integrated optical device includes an electro-absorption modulator disposed on a top surface of an optical waveguide. The electro-absorption modulator includes germanium disposed in a cavity between an n-type doped silicon sidewall and a p-type doped silicon sidewall. By applying a voltage between the n-type doped silicon sidewall and the p-type doped silicon sidewall, an electric field can be generated in a plane of the optical waveguide, but perpendicular to a propagation direction of the optical signal. This electric field shifts a band gap of the germanium, thereby modulating the optical signal.
    Type: Grant
    Filed: April 14, 2014
    Date of Patent: September 22, 2015
    Assignee: ORACLE INTERNATIONAL CORPORATION
    Inventors: John E. Cunningham, Jin Yao, Ivan Shubin, Guoliang Li, Xuezhe Zheng, Shiyun Lin, Hiren D. Thacker, Stevan S. Djordjevic, Ashok V. Krishnamoorthy