Patents by Inventor Boris Stefanov
Boris Stefanov 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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Publication number: 20120134663Abstract: A reflector assembly is disclosed that may include a housing; a fiber stud disposed within the housing; a filter lens having an OTDR reflective layer, the filter lens located downstream from the fiber stud and receiving light energy from the fiber stud, and configured to be transparent for light within a communication wavelength band and reflective within a diagnostic wavelength band.Type: ApplicationFiled: November 29, 2010Publication date: May 31, 2012Inventors: Hongsheng Wang, Richard Chen, Zemer Mizrahi, Ali Ouali, Boris Stefanov
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Patent number: 7633674Abstract: A photonic integrated circuit having a plurality of circuit components, is disclosed, which may include an MMI for splitting signal power passing therethrough among first and second optical pathways coupled to first and second outputs, respectively, of the MMI, thereby directing first and second percentages of the signal power along the first and the second optical pathways, respectively; and a photodetector integrated into the photonic integrated circuit and coupled to said first optical pathway for measuring a signal power level on said first optical pathway.Type: GrantFiled: October 20, 2008Date of Patent: December 15, 2009Assignee: Alphion CorporationInventors: Mohammad Laham, Boris Stefanov
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Publication number: 20090041454Abstract: A photonic integrated circuit having a plurality of circuit components, is disclosed, which may include an MMI for splitting signal power passing therethrough among first and second optical pathways coupled to first and second outputs, respectively, of the MMI, thereby directing first and second percentages of the signal power along the first and the second optical pathways, respectively; and a photodetector integrated into the photonic integrated circuit and coupled to said first optical pathway for measuring a signal power level on said first optical pathway.Type: ApplicationFiled: October 20, 2008Publication date: February 12, 2009Applicant: Alphion CorporationInventors: Mohammad Laham, Boris Stefanov
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Patent number: 7440179Abstract: The method of isolating faults internal to, for example, from tonic integrated circuits by diverting a portion of certain input and output signals to integrated photo detectors. By analyzing the admitted optical signal in each of plural photo detectors, falls within the circuit can be isolated.Type: GrantFiled: May 28, 2003Date of Patent: October 21, 2008Assignee: Alphion CorporationInventors: Mohammad Laham, Boris Stefanov
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Patent number: 7319555Abstract: Monitoring of the input power is performed on-chip and is used to monitor and maintain performance, detect failure and trigger network protection strategies. An optical power-monitoring technique uses a photodetector monolithically integrated with the semiconductor optical amplifier—Mach-Zehnder interferometer circuit to monitor the P2R device and keep the output stable while the input power varies.Type: GrantFiled: April 27, 2006Date of Patent: January 15, 2008Assignee: Alphion CorporationInventors: Ganesh Lakshminarayana, Ruomei Mu, Hongsheng Wang, Jithamithra Sarathy, Boris Stefanov
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Patent number: 7239768Abstract: A integrated optical circuit comprises an interferometer having a first optical path and a second optical path configured for regenerating an input signal entering the first path by interference at a first coupler between continuous wave (CW) signals from the two optical paths, and a third optical path configured such that a canceling signal passing therethrough cancels, at a second coupler, a traveling signal from the first arm. When the device is operated in a counter-propagative mode, the traveling signal is the CW signal from the first arm. When the device is operated in a co-propagative mode, the traveling signal is the input signal from the first arm.Type: GrantFiled: June 2, 2005Date of Patent: July 3, 2007Assignee: Alphion CorporationInventors: Ganesh Lakshminarayana, Jithamithra Sarathy, Boris Stefanov
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Patent number: 7190909Abstract: Method and apparatus are presented for the generation and detection of maintenance signals in an optical data network. The maintenance signals are such that they can be read both by high bit-rate and low bit-rate receivers. Detection of the maintenance signals occurs in two stages. In a low bit-rate first stage each nodal input port is sampled in a round robin fashion to detect the presence of a maintenance signal. In a high bit-rate second stage the maintenance signal is verified and read by a high speed receiver, along with other high bit-rate information transmitted with it. One second stage high speed receiver is shared among M input channels for cost and circuit efficiency.Type: GrantFiled: June 14, 2002Date of Patent: March 13, 2007Assignee: Alphion CorporationInventors: Jayanta Das, Ganesh Lakshminarayana, Kuo-Ming Lee, Roman Antosik, Scott Kaminski, Jithamithra Sarathy, Boris Stefanov, Ronald Simprini, Bharat Dave
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Publication number: 20070008613Abstract: Monitoring of the input power is performed on-chip and is used to monitor and maintain performance, detect failure and trigger network protection strategies. An optical power-monitoring technique uses a photodetector monolithically integrated with the semiconductor optical amplifier—Mach-Zehnder interferometer circuit to monitor the P2R device and keep the output stable while the input power varies.Type: ApplicationFiled: April 27, 2006Publication date: January 11, 2007Inventors: Ganesh Lakshminarayana, Ruomei Mu, Hongsheng Wang, Jithamithra Sarathy, Boris Stefanov
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Publication number: 20060182440Abstract: A robust nonblocking switch architecture is presented, in the first and final stages made of switch modules which have extra, unallocated, input and output ports beyond those necessary to render the switch architecture nonblocking. Each middle stage has an extra switch module, affording it spare unallocated ports as well. A method of isolating a fault is also presented, given the robust switching architecture. Operating on each stage one at a time, the switching architecture is reconnected so as to bypass either the input, the output, or both the input and the output ports of the switch module in such stage impacted in the faulted signal path. Such method allows the isolation of the faulty switch module, and can be done automatically, with either external apparatus, or integrated fault isolation equipment.Type: ApplicationFiled: April 18, 2006Publication date: August 17, 2006Inventors: Boris Stefanov, Mohammad Laham, Kevin Beach, Scott Kaminski
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Method and apparatus for bit-rate and format insensitive performance monitoring of lightwave signals
Patent number: 7009210Abstract: A method and apparatus for a tunable optical spectrum analyzer that can measure the optical spectrum of a demultiplexed DWDM signal are presented. The signal level and Optical Signal to Noise Ratio (OSNR) of an individual channel of the DWDM signal can be obtained from the measured optical spectrum. The device employs a rapid tuning and detection technique to obtain the optical spectrum of the incoming signal. In a preferred embodiment the apparatus is fabricated on a single chip resulting in a compact measurement device. Using the device of the preferred embodiment, single channel OSNR can be determined in as small a time interval as approximately 225 microseconds. Using an array of these devices an entire DWDM mixed signal can be monitored as to OP and OSNR in the same time interval.Type: GrantFiled: May 9, 2001Date of Patent: March 7, 2006Assignee: Alphion CorporationInventors: Jithamithra Sarathy, Chinnabbu Ekambaram, David Lidsky, Bharat Dave, Boris Stefanov, Tan B. Thai, Ronald Simprini, Julio Martinez, Gaurav Naik -
Publication number: 20060018587Abstract: A integrated optical circuit comprises an interferometer having a first optical path and a second optical path configured for regenerating an input signal entering the first path by interference at a first coupler between continuous wave (CW) signals from the two optical paths, and a third optical path configured such that a canceling signal passing therethrough cancels, at a second coupler, a traveling signal from the first arm. When the device is operated in a counter-propagative mode, the traveling signal is the CW signal from the first arm. When the device is operated in a co-propagative mode, the traveling signal is the input signal from the first arm.Type: ApplicationFiled: June 2, 2005Publication date: January 26, 2006Inventors: Ganesh Lakshminarayana, Jithamithra Sarathy, Boris Stefanov
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Patent number: 6856767Abstract: The present invention provides an optical signal quality selection system for optimizing the quality of information transmission. The system splits an incoming optical signal into two equal signals. The split signals are evaluated in optical performance monitors, transmitting an electrical output message to a signal selector relating to the quality of the respective signal. A second electrical message is sent from the optical performance generator to an alarm indicator signal generator, which sends an optical signal to the signal selector to drop the one of the split signals and transmit the non-dropped split signal. An unequipped optical signal from an optical idle signal generator is triggered if no active optical signal is being transmitted.Type: GrantFiled: April 18, 2001Date of Patent: February 15, 2005Assignee: Alphion CorporationInventors: Mohammad Laham, Raj Acharya, Roman Antosik, Jayantha Das, Bharat Dave, Chinnabbu Ekambaram, Khem Gandhi, Frank Hujber, David Lowe, Frederick Renner, Jiten Sarathy, Ronald Simprini, Boris Stefanov, Tan Thai, Ravi Vora
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Publication number: 20040100257Abstract: An Abstract was inadvertently omitted from the original filing of the application back on May 28, 2003, and we ask that you kindly add the following paragraph at the end of the application: “The method of isolating faults internal to, for example, from tonic integrated circuits by diverting a portion of certain input and output signals to integrated photo detectors. By analyzing the admitted optical signal in each of plural photo detectors, falls within the circuit can be isolated.Type: ApplicationFiled: May 28, 2003Publication date: May 27, 2004Inventors: Mohammad Laham, Boris Stefanov
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Patent number: 6727991Abstract: A method and circuit are presented for an all-optical format independent preprocessor that processes an arbitrary optical input signal by converting a NRZ signal to a PRZ signal, or if the input optical signal is RZ, by merely amplifying it. The method involves subtracting a delayed copy of the signal from the original, thereby effectively doubling its frequency, and inserting a pulse at each transition of the original signal, whether rising or falling. In a preferred embodiment this stage is implemented via an integrated SOA in each arm of an asymmetric interferometric device. The asymmetry consists of a delay element in one arm. In a preferred embodiment the entire device is fabricated on a semiconductor substrate, allowing for compactness as well as minimization of interconnectivity losses and overall power consumption. The output of the preprocessor, having a significant frequency component at its original clock rate, can then be fed to a clock recovery stage for all-optical clock recovery.Type: GrantFiled: July 15, 2002Date of Patent: April 27, 2004Assignee: Alphion CorporationInventors: Julio Martinez, Kwang Kim, Olga Nedzhvetskaya, Doruk Engin, Jiten Sarathy, Roman Antosik, Bharat Dave, Michael Evans, David Lidsky, Ronald Simprini, Boris Stefanov, Tan Thai
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Patent number: 6724484Abstract: A method and circuit are presented for an all-optical format independent preprocessor that processes an arbitrary optical input signal by converting a NRZ signal to a PRZ signal, or if the input optical signal is RZ, by merely amplifying it. The method involves subtracting a delayed copy of the signal from the original, thereby effectively doubling its frequency, and inserting a pulse at each transition of the original signal, whether rising or falling. In a preferred embodiment this stage is implemented via an integrated SOA in each arm of an asymmetric interferometric device. The asymmetry consists of a delay element in one arm. In a preferred embodiment the entire device is fabricated on a semiconductor substrate, allowing for compactness as well as minimization of interconnectivity losses and overall power consumption. The output of the preprocessor, having a significant frequency component at its original clock rate, can then be fed to a clock recovery stage for all-optical clock recovery.Type: GrantFiled: July 15, 2002Date of Patent: April 20, 2004Assignee: Alphion CorporationInventors: Julio Martinez, Kwang Kim, Olga Nedzhvetskaya, Doruk Engin, Jiten Sarathy, Roman Antosik, Bharat Dave, Michael Evans, David Lidsky, Ronald Simprini, Boris Stefanov, Tan Thai
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Patent number: 6678086Abstract: A method and circuit are presented for the all optical recovery of the clock signal from an arbitrary optical data signal. The method involves two stages. A first stage preprocesses the optical signal by converting a NRZ signal to a PRZ signal, or if the input optical signal is RZ, by merely amplifying it. In a preferred embodiment this stage is implemented via an integrated SOA in each arm of an asymmetric interferometric device. The output of the preprocessing stage is fed to a clock recovery stage, which consists of a symmetric interferometer that locks on to the inherent clock signal by using the second stage input signal to trigger two optical sources to self oscillate at the clock rate. In a preferred embodiment the second stage is implemented via SOAs integrated in the arms of an interferometer, with two DFB lasers as terminuses. The output of the interferometer is an optical clock signal at the clock rate of the original input.Type: GrantFiled: July 15, 2002Date of Patent: January 13, 2004Assignee: Alphion CorporationInventors: Bharat Dave, Doruk Engin, Kwang Kim, Mohammad Laham, Julio Martinez, Olga Nedzhvetskaya, Jithamithra Sarathy, Ronald Simprini, Boris Stefanov, Tan Buu Thai
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Patent number: 6671467Abstract: A method and circuit are presented for the all optical recovery of the clock signal from an arbitrary optical data signal. The method involves two stages. A first stage preprocesses the optical signal by converting a NRZ signal to a PRZ signal, or if the input optical signal is RZ, by merely amplifying it. In a preferred embodiment this stage is implemented via an integrated SOA in each arm of an asymmetric interferometric device. The output of the preprocessing stage is fed to a clock recovery stage, which consists of a symmetric interferometer that locks on to the inherent clock signal by using the second stage input signal to trigger two optical sources to self oscillate at the clock rate. In a preferred embodiment the second stage is implemented via SOAs integrated in the arms of an interferometer, with two DFB lasers as terminuses. The output of the interferometer is an optical clock signal at the clock rate of the original input.Type: GrantFiled: July 15, 2002Date of Patent: December 30, 2003Assignee: Alphion CorporationInventors: Bharat Dave, Doruk Engin, Kwang Kim, Mohammad Laham, Julio Martinez, Olga Nedzhvetskaya, Jithamithra Sarathy, Roanld Simprini, Boris Stefanov, Tan Buu Thai
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Patent number: 6646794Abstract: A method and circuit are presented for an all-optical format independent preprocessor that processes an arbitrary optical input signal by converting a NRZ signal to a PRZ signal, or if the input optical signal is RZ, by merely amplifying it. The method involves subtracting a delayed copy of the signal from the original, thereby effectively doubling its frequency, and inserting a pulse at each transition of the original signal, whether rising or falling. In a preferred embodiment this stage is implemented via an integrated SOA in each arm of an asymmetric interferometric device. The asymmetry consists of a delay element in one arm. In a preferred embodiment the entire device is fabricated on a semiconductor substrate, allowing for compactness as well as minimization of interconnectivity losses and overall power consumption. The output of the preprocessor, having a significant frequency component at its original clock rate, can then be fed to a clock recovery stage for all-optical clock recovery.Type: GrantFiled: July 15, 2002Date of Patent: November 11, 2003Assignee: Alphion CorporationInventors: Julio Martinez, Kwang Kim, Olga Nedzhvetskaya, Doruk Engin, Jiten Sarathy, Bharat Dave, Ronald Simprini, Boris Stefanov, Tan Thai
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Patent number: 6636318Abstract: A method and system for AO3R functionality is presented. The system includes an AO2R device followed by an AOCR clock recovery module and an AOR retiming device. The AOR retiming device takes as input a recovered clock signal extracted from the output of the AO2R by the AOCR clock recovery module. The output is the recovered clock signal gated by the regenerated and reshaped input signal, and a monitor circuit is used to set the optimum operations of the retiming device. In a first embodiment the output of the AOR retiming device is fed to an AOC code and wavelength conversion output stage, which returns the signal to the NRZ coding, on a service wavelength converted to match the fixed wavelength connection with the DWDM transmission system. In a second embodiment the code conversion is incorporated into the AOR retiming device, and wavelength conversion is accomplished in the AOCR clock recovery device.Type: GrantFiled: October 5, 2001Date of Patent: October 21, 2003Assignee: Alphion Corp.Inventors: Jithamithra Sarathy, Bharat Dave, Boris Stefanov, Ronald Simprini, Tan B. Thai, Roman Antosik, Aleksandr Miglo, Olga Nedzhvetska, Kwang Kim, Doruk Engin
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Patent number: 6624924Abstract: A method and circuit are presented for the all optical recovery of the clock signal from an arbitrary optical data signal. The method involves two stages. A first stage preprocesses the optical signal by converting a NRZ signal to a PRZ signal, or if the input optical signal is RZ, by merely amplifying it. In a preferred embodiment this stage is implemented via an integrated SOA in each arm of an asymmetric interferometric device. The output of the preprocessing stage is fed to a clock recovery stage, which consists of a symmetric interferometer that locks on to the inherent clock signal by using the second stage input signal to trigger two optical sources to self oscillate at the clock rate. In a preferred embodiment the second stage is implemented via SOAs integrated in the arms of an interferometer, with two DFB lasers as terminuses. The output of the interferometer is an optical clock signal at the clock rate of the original input.Type: GrantFiled: July 15, 2002Date of Patent: September 23, 2003Assignee: Alphion Corp.Inventors: Bharat Dave, Doruk Engin, Kwang Kim, Mohammad Laham, Julio Martinez, Olga Nedzhvetskaya, Jithamithra Sarathy, Ronald Simprini, Boris Stefanov, Tan Buu Thai