Patents by Inventor Suhas P. Bhandare
Suhas P. Bhandare 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: 11385483Abstract: An optical Mach-Zehnder superstructure modulator and method that can simultaneously linearize in-phase and quadrature components of optically modulated optical signals and reduce the modulated optical insertion loss (MOIL) by in-phase addition of the in-phase and quadrature components of an amplitude and/or phase modulated optical signal using two high-speed phase modulators embedded in the optical Mach-Zehnder superstructure modulator.Type: GrantFiled: November 17, 2020Date of Patent: July 12, 2022Assignee: II-VI DELAWARE, INC.Inventors: Suhas P. Bhandare, Daniel Mahgerefteh
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Publication number: 20210072566Abstract: An optical Mach-Zehnder superstructure modulator and method that can simultaneously linearize in-phase and quadrature components of optically modulated optical signals and reduce the modulated optical insertion loss (MOIL) by in-phase addition of the in-phase and quadrature components of an amplitude and/or phase modulated optical signal using two high-speed phase modulators embedded in the optical Mach-Zehnder superstructure modulator.Type: ApplicationFiled: November 17, 2020Publication date: March 11, 2021Inventors: Suhas P. BHANDARE, Daniel MAHGEREFTEH
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Patent number: 10871662Abstract: An optical Mach-Zehnder superstructure modulator and method that can simultaneously linearize in-phase and quadrature components of optically modulated optical signals and reduce the modulated optical insertion loss (MOIL) by in-phase addition of the in-phase and quadrature components of an amplitude and/or phase modulated optical signal using two high-speed phase modulators embedded in the optical Mach-Zehnder superstructure modulator.Type: GrantFiled: September 4, 2019Date of Patent: December 22, 2020Assignee: II-VI Delaware, Inc.Inventors: Suhas P. Bhandare, Daniel Mahgerefteh
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Publication number: 20200081276Abstract: An optical Mach-Zehnder superstructure modulator and method that can simultaneously linearize in-phase and quadrature components of optically modulated optical signals and reduce the modulated optical insertion loss (MOIL) by in-phase addition of the in-phase and quadrature components of an amplitude and/or phase modulated optical signal using two high-speed phase modulators embedded in the optical Mach-Zehnder superstructure modulator.Type: ApplicationFiled: September 4, 2019Publication date: March 12, 2020Applicant: Finisar CorporationInventors: Suhas P. Bhandare, Daniel Mahgerefteh
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Patent number: 10218446Abstract: A method and apparatus for characterizing and compensating optical impairments in an optical transmitter includes operating an optical transmitter comprising a first and second parent MZ, each comprising a plurality of child MZ modulators that are biased at respective initial operating points. An electro-optic RF transfer function is generated for each of the plurality of child MZ modulators. Curve fitting parameters are determined for each of the plurality of electro-optic RF transfer functions and operating points of each child MZ modulator are determined using the curve fitting parameters. An IQ power imbalance is determined using the curve fitting parameters. Initial RF drive power levels are determined that compensate for the determined IQ power imbalance. The XY power imbalance is determined for initial RF drive power levels using the curve fitting parameters.Type: GrantFiled: March 7, 2018Date of Patent: February 26, 2019Assignee: Finisar CorporationInventors: Suhas P. Bhandare, Heider N. Ereifej, Ihab E. Khalouf, Mark Colyar
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Publication number: 20180198531Abstract: A method and apparatus for characterizing and compensating optical impairments in an optical transmitter includes operating an optical transmitter comprising a first and second parent MZ, each comprising a plurality of child MZ modulators that are biased at respective initial operating points. An electro-optic RF transfer function is generated for each of the plurality of child MZ modulators. Curve fitting parameters are determined for each of the plurality of electro-optic RF transfer functions and operating points of each child MZ modulator are determined using the curve fitting parameters. An IQ power imbalance is determined using the curve fitting parameters. Initial RF drive power levels are determined that compensate for the determined IQ power imbalance. The XY power imbalance is determined for initial RF drive power levels using the curve fitting parameters.Type: ApplicationFiled: March 7, 2018Publication date: July 12, 2018Applicant: Finisar CorporationInventors: Suhas P. Bhandare, Heider N. Ereifej, Ihab E. Khalouf, Mark Colyar
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Patent number: 9917649Abstract: A method and apparatus for characterizing and compensating optical impairments in an optical transmitter includes operating an optical transmitter comprising a first and second parent MZ, each comprising a plurality of child MZ modulators that are biased at respective initial operating points. An electro-optic RF transfer function is generated for each of the plurality of child MZ modulators. Curve fitting parameters are determined for each of the plurality of electro-optic RF transfer functions and operating points of each child MZ modulator are determined using the curve fitting parameters. An IQ power imbalance is determined using the curve fitting parameters. Initial RF drive power levels are determined that compensate for the determined IQ power imbalance. The XY power imbalance is determined for initial RF drive power levels using the curve fitting parameters.Type: GrantFiled: April 16, 2017Date of Patent: March 13, 2018Assignee: Finisar CorporationInventors: Suhas P. Bhandare, Heider N. Ereifej, Ihab E. Khalouf, Mark Colyar
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Publication number: 20170222725Abstract: A method and apparatus for characterizing and compensating optical impairments in an optical transmitter includes operating an optical transmitter comprising a first and second parent MZ, each comprising a plurality of child MZ modulators that are biased at respective initial operating points. An electro-optic RF transfer function is generated for each of the plurality of child MZ modulators. Curve fitting parameters are determined for each of the plurality of electro-optic RF transfer functions and operating points of each child MZ modulator are determined using the curve fitting parameters. An IQ power imbalance is determined using the curve fitting parameters. Initial RF drive power levels are determined that compensate for the determined IQ power imbalance. The XY power imbalance is determined for initial RF drive power levels using the curve fitting parameters.Type: ApplicationFiled: April 16, 2017Publication date: August 3, 2017Applicant: Finisar CorporationInventors: Suhas P. Bhandare, Heider N. Ereifej, Ihab E. Khalouf, Mark Colyar
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Patent number: 9692518Abstract: A DP-QPSK optical transmitter includes an outer MZM comprising a first parent MZM comprising a first child MZM and a second child MZM that modulates a QPSK signal with a first polarization. A second parent MZM includes a first child MZM and a second child MZM that modulates a QPSK signal with a second polarization. The outer Mach-Zehnder modulator multiplexes the first and second polarization embedded into a dual-polarization QPSK signal generation. A first optical detector detects the QPSK signal generated by the first parent MZM with the first polarization. A second optical detector optical detects the QPSK signal generated by the second parent Mach-Zehnder modulator with the second polarization. A bias control circuit generates bias signals on at least one output that stabilize the DP-QPSK signal in response to signals generated by the first and second optical detector using electrical time division multiplexing.Type: GrantFiled: July 17, 2013Date of Patent: June 27, 2017Assignee: Finisar CorporationInventors: Suhas P. Bhandare, Heider N. Ereifej, Kyu Kim, Mark Colyar
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Patent number: 9654226Abstract: A method and apparatus for characterizing and compensating optical impairments in an optical transmitter includes operating an optical transmitter comprising a first and second parent MZ, each comprising a plurality of child MZ modulators that are biased at respective initial operating points. An electro-optic RF transfer function is generated for each of the plurality of child MZ modulators. Curve fitting parameters are determined for each of the plurality of electro-optic RF transfer functions and operating points of each child MZ modulator are determined using the curve fitting parameters. An IQ power imbalance is determined using the curve fitting parameters. Initial RF drive power levels are determined that compensate for the determined IQ power imbalance. The XY power imbalance is determined for initial RF drive power levels using the curve fitting parameters.Type: GrantFiled: December 19, 2015Date of Patent: May 16, 2017Assignee: Finisar CorporationInventors: Suhas P. Bhandare, Heider N. Ereifej, Ihab E. Khalouf, Mark Colyar
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Patent number: 9494810Abstract: Embodiments include a method and apparatus used for automatic bias stabilization of a DP IQM based on MZM for transmitting DP-QPSK optical data and/or DP-16QAM optical data. The apparatus simultaneously dithers DC-bias voltages of in-phase child, quadrature-phase child, and parent MZMs with three different dither patterns in time-domain which are mutually orthogonal to each other in the frequency-domain for X and Y polarization IQ modulators. Tap monitor photodiodes detect an interference term between these three dither patterns for each polarization. The interference term is sampled using an ADC in the time domain. The time-synchronous detection method may solve a set of three simultaneous linear partial differential equations with three unknowns to compute controlled DC-bias voltages to set on the respective MZM with a solution set which may iteratively converge to a unique solution, thereby biasing the child MZM in dual-polarization IQM to transmission minimum and parent MZM in quadrature transmission.Type: GrantFiled: March 24, 2016Date of Patent: November 15, 2016Assignee: FINISAR CORPORATIONInventors: Suhas P. Bhandare, Mark Colyar, David Meloche, Terence D. Grenda, Chris Stook, Heider N. Ereifej, John DeAndrea
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Publication number: 20160282638Abstract: Embodiments include a method and apparatus used for automatic bias stabilization of a DP IQM based on MZM for transmitting DP-QPSK optical data and/or DP-16 QAM optical data. The apparatus simultaneously dithers DC-bias voltages of in-phase child, quadrature-phase child, and parent MZMs with three different dither patterns in time-domain which are mutually orthogonal to each other in the frequency-domain for X and Y polarization IQ modulators. Tap monitor photodiodes detect an interference term between these three dither patterns for each polarization. The interference term is sampled using an ADC in the time domain. The time-synchronous detection method may solve a set of three simultaneous linear partial differential equations with three unknowns to compute controlled DC-bias voltages to set on the respective MZM with a solution set which may iteratively converge to a unique solution, thereby biasing the child MZM in dual-polarization IQM to transmission minimum and parent MZM in quadrature transmission.Type: ApplicationFiled: March 24, 2016Publication date: September 29, 2016Inventors: Suhas P. Bhandare, Mark Colyar, David Meloche, Terence D. Grenda, Chris Stook, Heider N. Ereifej, John DeAndrea
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Publication number: 20150207569Abstract: A DP-QPSK optical transmitter includes an outer MZM comprising a first parent MZM comprising a first child MZM and a second child MZM that modulates a QPSK signal with a first polarization. A second parent MZM includes a first child MZM and a second child MZM that modulates a QPSK signal with a second polarization. The outer Mach-Zehnder modulator multiplexes the first and second polarization embedded into a dual-polarization QPSK signal generation. A first optical detector detects the QPSK signal generated by the first parent MZM with the first polarization. A second optical detector optical detects the QPSK signal generated by the second parent Mach-Zehnder modulator with the second polarization. A bias control circuit generates bias signals on at least one output that stabilize the DP-QPSK signal in response to signals generated by the first and second optical detector using electrical time division multiplexing.Type: ApplicationFiled: July 17, 2013Publication date: July 23, 2015Applicant: Finisar CorporationInventors: Suhas P. Bhandare, Heider N. Ereifej, Kyu Kim, Mark Colyar
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Patent number: 8849129Abstract: A DP-QPSK optical transmitter includes an outer MZM comprising a first parent MZM comprising a first child MZM and a second child MZM that modulates a QPSK signal with a first polarization. A second parent MZM includes a first child MZM and a second child MZM that modulates a QPSK signal with a second polarization. The outer Mach-Zehnder modulator multiplexes the first and second polarization embedded into a dual-polarization QPSK signal generation. A first optical detector detects the QPSK signal generated by the first parent MZM with the first polarization. A second optical detector optical detects the QPSK signal generated by the second parent Mach-Zehnder modulator with the second polarization. A bias control circuit generates bias signals on at least one output that stabilize the DP-QPSK signal in response to signals generated by the first and second optical detector using electrical time division multiplexing.Type: GrantFiled: July 20, 2012Date of Patent: September 30, 2014Assignee: Finisar CorporationInventors: Suhas P. Bhandare, Heider N. Ereifej, Kyu Kim, Mark Colyar
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Publication number: 20140023368Abstract: A DP-QPSK optical transmitter includes an outer MZM comprising a first parent MZM comprising a first child MZM and a second child MZM that modulates a QPSK signal with a first polarization. A second parent MZM includes a first child MZM and a second child MZM that modulates a QPSK signal with a second polarization. The outer Mach-Zehnder modulator multiplexes the first and second polarization embedded into a dual-polarization QPSK signal generation. A first optical detector detects the QPSK signal generated by the first parent MZM with the first polarization. A second optical detector optical detects the QPSK signal generated by the second parent Mach-Zehnder modulator with the second polarization. A bias control circuit generates bias signals on at least one output that stabilize the DP-QPSK signal in response to signals generated by the first and second optical detector using electrical time division multiplexing.Type: ApplicationFiled: July 20, 2012Publication date: January 23, 2014Applicant: FINISAR CORPORATIONInventors: Suhas P. Bhandare, Heider Ereifej, Kyu Kim, Mark Colyar
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Patent number: 8126338Abstract: Repeaterless transmission of differential phase-shift keying (DPSK) at 10.7 Gb/s over at least 304 km of standard single-mode fiber is obtained through use of a coherent optical receiver including electronic dispersion compensation. High receiver sensitivity and high tolerance to nonlinearities of DPSK, allow overcoming a total link loss of 58 dB with a 3 dB system margin, through use in the receiver of heterodyne detection to preserve phase distortions resulting from chromatic dispersion, to permit electronic dispersion compensation to be used.Type: GrantFiled: October 29, 2008Date of Patent: February 28, 2012Assignee: Discovery Semiconductors, Inc.Inventors: Christoph T. Wree, Suhas P. Bhandare, Donald A. Becker, Daniel R. Mohr, Abhay M. Joshi
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Publication number: 20090142069Abstract: Repeaterless transmission of differential phase-shift keying (DPSK) at 10.7 Gb/s over at least 304 km of standard single-mode fiber is obtained through use of a coherent optical receiver including electronic dispersion compensation. High receiver sensitivity and high tolerance to nonlinearities of DPSK, allow overcoming a total link loss of 58 dB with a 3 dB system margin, through use in the receiver of heterodyne detection to preserve phase distortions resulting from chromatic dispersion, to permit electronic dispersion compensation to be used.Type: ApplicationFiled: October 29, 2008Publication date: June 4, 2009Inventors: Christoph T. Wree, Suhas P. Bhandare, Donald A. Becker, Daniel R. Mohr, Abhay M. Joshi