Patents by Inventor David Menashe
David Menashe 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: 8817365Abstract: Methods for optimizing a noise figure of a variable gain hybrid amplifier (HA) which includes a variable gain Raman amplifier with adjustable average gain GR and gain tilt TR and a variable gain lumped amplifier with adjustable average gain GL and gain tilt TL. In various embodiments, the methods include receiving as input a required hybrid amplifier average gain GH value and a required gain tilt TH value and deriving a set of GR, TR, GL and TL values which yield an optimal optimized hybrid amplifier NF and satisfy the conditions GR+GL=GH and that TR+TL is within a specified hybrid amplifier operating tilt range. In some embodiments, the derived TR and TL values satisfy the condition TR+TL=TH.Type: GrantFiled: July 19, 2012Date of Patent: August 26, 2014Assignee: Finisar Israel Ltd.Inventors: Tomer Eliyahu, Eyal Sarid, Uri Ghera, David Menashe
-
Patent number: 8643941Abstract: Apparatus and method for gain measurement and control of a Distributed Raman Amplifier (DRA). Various embodiments of the apparatus include a detection unit operative to measure, during operation of the DRA, the optical power of a filtered component of the light entering the DRA from the transmission fiber and a gain calculation and control unit coupled to the detection unit and operative to calculate a signal Raman gain property from the measured optical power. The filtered component may exemplarily be a result of passing the light through a band pass filter, a spectral filter with a given spectral shape or a notch filter. The signal Raman gain property may be an average on-off signal Raman gain, an average net signal Raman gain or a signal Raman gain tilt within a communication band. The apparatus and method may be used to operate the DRA in Automatic Gain Control, i.e. to maintain a required constant signal Raman gain and/or signal Raman gain tilt.Type: GrantFiled: November 16, 2010Date of Patent: February 4, 2014Assignee: Finisar Israel Ltd.Inventors: Uri Ghera, Alex Shlifer, Daniel Berger, Mark Zaacks, David Menashe
-
Publication number: 20140022626Abstract: Methods for optimizing a noise figure of a variable gain hybrid amplifier (HA) which includes a variable gain Raman amplifier with adjustable average gain GR and gain tilt TR and a variable gain lumped amplifier with adjustable average gain GL and gain tilt TL. In various embodiments, the methods include receiving as input a required hybrid amplifier average gain GH value and a required gain tilt TH value and deriving a set of GR, TR, GL and TL values which yield an optimal optimized hybrid amplifier NF and satisfy the conditions GR+GL=GH and that TR+TL is within a specified hybrid amplifier operating tilt range. In some embodiments, the derived TR and TL values satisfy the condition TR+TL=TH.Type: ApplicationFiled: July 19, 2012Publication date: January 23, 2014Applicant: RED-C OPTICAL NETWORKS LTD.Inventors: Tomer Eliyahu, Eyal Sarid, Uri Ghera, David Menashe
-
Patent number: 8576481Abstract: Method and apparatus for detecting an opening in a transmission fiber connecting a discrete gain unit to a pump unit of a Remote Optically Pumped Amplifier (ROPA) system. The method comprises measuring an optical power entering the pump unit from the transmission fiber, the optical power being in a selected wavelength range, and establishing that the optical power lacks an ASE noise power component generated by the gain unit. The lack of this component indicates the presence of a break or opening in the transmission fiber, and triggers corrective action whereby pump lasers within the pump unit are shut down or have their power reduced to a safe level.Type: GrantFiled: August 3, 2010Date of Patent: November 5, 2013Assignee: Finisar Israel Ltd.Inventors: Mark Zaacks, Uri Ghera, David Menashe
-
Publication number: 20120033293Abstract: Method and apparatus for detecting an opening in a transmission fiber connecting a discrete gain unit to a pump unit of a Remote Optically Pumped Amplifier (ROPA) system. The method comprises measuring an optical power entering the pump unit from the transmission fiber, the optical power being in a selected wavelength range, and establishing that the optical power lacks an ASE noise power component generated by the gain unit. The lack of this component indicates the presence of a break or opening in the transmission fiber, and triggers corrective action whereby pump lasers within the pump unit are shut down or have their power reduced to a safe level.Type: ApplicationFiled: August 3, 2010Publication date: February 9, 2012Applicant: RED-C OPTICAL NETWORKS LTD.Inventors: MARK ZAACKS, URI GHERA, DAVID MENASHE
-
Publication number: 20110141552Abstract: Apparatus and method for gain measurement and control of a Distributed Raman Amplifier (DRA). Various embodiments of the apparatus include a detection unit operative to measure, during operation of the DRA, the optical power of a filtered component of the light entering the DRA from the transmission fiber and a gain calculation and control unit coupled to the detection unit and operative to calculate a signal Raman gain property from the measured optical power. The filtered component may exemplarily be a result of passing the light through a band pass filter, a spectral filter with a given spectral shape or a notch filter. The signal Raman gain property may be an average on-off signal Raman gain, an average net signal Raman gain or a signal Raman gain tilt within a communication band. The apparatus and method may be used to operate the DRA in Automatic Gain Control, i.e. to maintain a required constant signal Raman gain and/or signal Raman gain tilt.Type: ApplicationFiled: November 16, 2010Publication date: June 16, 2011Applicant: RED-C OPTICAL NETWORKS LTD.Inventors: Uri Ghera, Alex Shlifer, Daniel Berger, Mark Zaacks, David Menashe
-
Patent number: 7773884Abstract: A method and apparatus for automatic shut-down and start-up of optical amplifiers in wavelength division multiplexed (WDM) optical networks include use of an optical channel monitor (OCM) to monitor loss and return of an input signal. By using the OCM to separately monitor the power level of each individual channel, it is possible to detect loss of all channels or return of a single channel even in the presence of ASE at the amplifier input. The OCM receives a fraction of the input power to the amplifier via an optical tap at the amplifier input, and provides an electrical output to a control unit corresponding to the optical power level of each individual WDM channel. Based on this electrical output, the control sends a shut-down or start-up signal to the pump unit within the amplifier.Type: GrantFiled: October 5, 2006Date of Patent: August 10, 2010Assignee: Red - C Optical Newworks Ltd.Inventors: Uri Ghera, David Menashe
-
Patent number: 7440177Abstract: A system and method for providing eye-safety protection during operation of a lumped optical amplifier. The method is based on monitoring of continuous out-of-band Raman amplified spontaneous scattering (ASS) created by the amplified signal in an optical communication network span coupled to an output port of the lumped optical amplifier. The system includes at least one gain stage for providing an amplified signal introduced into the span, a monitoring unit for performing the continuous Raman ASS monitoring, and a control unit operative to detect and analyze in real-time changes in the ASS power, and upon determination that such changes indicate an open span, to reduce the power of the amplified signal or shut down the gain stage.Type: GrantFiled: March 29, 2007Date of Patent: October 21, 2008Assignee: EDC Optical Networks Inc.Inventors: Uri Ghera, Alex Shlifer, David Menashe
-
Patent number: 7385754Abstract: Efficient wavelength calibration in a WDM optical amplifier that includes an optical channel monitor (OCM) is obtained by introducing a notch into the amplified spontaneous emission (ASE) noise spectrum of the amplifier outside a WDM transmission band, and having the OCM detect the notch and use the notch as a reference to calibrate the wavelength measurement. The notch is introduced into the ASE noise spectrum using a notch filter, which is preferably incorporated in a gain flattening filter (GFF).Type: GrantFiled: March 6, 2006Date of Patent: June 10, 2008Assignee: REDC Optical Networks Inc.Inventors: Uri Ghera, Alex Shlifer, Tomer Eliyahu, David Menashe
-
Patent number: 7283292Abstract: A system and method for providing eye-safety protection during operation of distributed Raman amplifiers based on the application of continuous out-of-band amplified spontaneous scattering (ASS) monitoring in an optical communication network span coupled to the Raman amplifier, and real-time detection and analysis of changes in the monitored ASS power level, The system includes at least one Raman pump for introducing Raman energy into the span, a monitoring unit for performing the continuous ASS monitoring, and a control unit operative to detect and analyze in real-time changes in the ASS power, and upon determination that such changes indicate an open span, to reduce the level of the Raman pump energy entering the span to a safe level.Type: GrantFiled: August 13, 2006Date of Patent: October 16, 2007Assignee: Redc Optical Networking Ltd.Inventors: Uri Ghera, Daniel Berger, David Menashe
-
Publication number: 20070206273Abstract: Efficient wavelength calibration in a WDM optical amplifier that includes an optical channel monitor (OCM) is obtained by introducing a notch into the amplified spontaneous emission (ASE) noise spectrum of the amplifier outside a WDM transmission band, and having the OCM detect the notch and use the notch as a reference to calibrate the wavelength measurement. The notch is introduced into the ASE noise spectrum using a notch filter, which is preferably incorporated in a gain flattening filter (GFF).Type: ApplicationFiled: March 6, 2006Publication date: September 6, 2007Inventors: Uri Ghera, Alex Shlifer, Tomer Eliyahu, David Menashe
-
Publication number: 20070177254Abstract: A system and method for providing eye-safety protection during operation of a lumped optical amplifier. The method is based on monitoring of continuous out-of-band Raman amplified spontaneous scattering (ASS) created by the amplified signal in an optical communication network span coupled to an output port of the lumped optical amplifier. The system includes at least one gain stage for providing an amplified signal introduced into the span, a monitoring unit for performing the continuous Raman ASS monitoring, and a control unit operative to detect and analyze in real-time changes in the ASS power, and upon determination that such changes indicate an open span, to reduce the power of the amplified signal or shut down the gain stage.Type: ApplicationFiled: March 29, 2007Publication date: August 2, 2007Applicant: RED-C Optical Networks Ltd.Inventors: Uri Ghera, Alex Shlifer, David Menashe
-
Publication number: 20070098411Abstract: A method and apparatus for automatic shut-down and start-up of optical amplifiers in wavelength division multiplexed (WDM) optical networks include use of an optical channel monitor (OCM) to monitor loss and return of an input signal. By using the OCM to separately monitor the power level of each individual channel, it is possible to detect loss of all channels or return of a single channel even in the presence of ASE at the amplifier input. The OCM receives a fraction of the input power to the amplifier via an optical tap at the amplifier input, and provides an electrical output to a control unit corresponding to the optical power level of each individual WDM channel. Based on this electrical output, the control sends a shut-down or start-up signal to the pump unit within the amplifier.Type: ApplicationFiled: October 5, 2006Publication date: May 3, 2007Applicant: RED-C Optical Networks Ltd.Inventors: URI GHERA, David Menashe
-
Publication number: 20060274402Abstract: A system and method for providing eye-safety protection during operation of distributed Raman amplifiers based on the application of continuous out-of-band amplified spontaneous scattering (ASS) monitoring in an optical communication network span coupled to the Raman amplifier, and real-time detection and analysis of changes in the monitored ASS power level, The system includes at least one Raman pump for introducing Raman energy into the span, a monitoring unit for performing the continuous ASS monitoring, and a control unit operative to detect and analyze in real-time changes in the ASS power, and upon determination that such changes indicate an open span, to reduce the level of the Raman pump energy entering the span to a safe level.Type: ApplicationFiled: August 13, 2006Publication date: December 7, 2006Applicant: RedC Optical Networking Ltd.Inventors: Uri Ghera, Daniel Berger, David Menashe
-
Patent number: 7116471Abstract: A system and method for providing eye-safety protection during operation of distributed Raman amplifiers based on the application of continuous out-of-band amplified spontaneous scattering (ASS) monitoring in an optical communication network span coupled to the Raman amplifier, and real-time detection and analysis of changes in the monitored ASS power level, The system includes at least one Raman pump for introducing Raman energy into the span, a monitoring unit for performing the continuous ASS monitoring, and a control unit operative to detect and analyze in real-time changes in the ASS power, and upon determination that such changes indicate an open span, to reduce the level of the Raman pump energy entering the span to a safe level.Type: GrantFiled: December 2, 2004Date of Patent: October 3, 2006Assignee: Redc Optical Networking Ltd.Inventors: Uri Ghera, Daniel Berger, Itzhak Filiba, David Menashe
-
Publication number: 20060119931Abstract: A system and method for providing eye-safety protection during operation of distributed Raman amplifiers based on the application of continuous out-of-band amplified spontaneous scattering (ASS) monitoring in an optical communication network span coupled to the Raman amplifier, and real-time detection and analysis of changes in the monitored ASS power level, The system includes at least one Raman pump for introducing Raman energy into the span, a monitoring unit for performing the continuous ASS monitoring, and a control unit operative to detect and analyze in real-time changes in the ASS power, and upon determination that such changes indicate an open span, to reduce the level of the Raman pump energy entering the span to a safe level.Type: ApplicationFiled: December 2, 2004Publication date: June 8, 2006Inventors: Uri Ghera, Daniel Berger, Itzhak Filiba, David Menashe
-
Patent number: 7023612Abstract: An apparatus for optical amplification that imparts to a narrow band optical amplifier, specifically an Erbium dope fiber amplifier (EDFA), gain properties found in wide band optical amplifiers. In one preferred embodiment, the apparatus comprises an EDFA and an externally attachable (to the EDFA) module that includes a single un-pumped Erbium doped fiber (EDF) connected to a gain flattening filter (GFF). The GFF may be internal or external to the module. In another embodiment, the apparatus comprises an EDFA and an externally attachable module having a plurality of un-doped EDFs with different lengths, switchably connectable to the GFF and the EDFA to provide the required wide-band gain properties.Type: GrantFiled: February 28, 2005Date of Patent: April 4, 2006Assignee: Red-C Optical Networking Ltd.Inventors: Uri Ghera, Alex Shlifer, David Menashe
-
Publication number: 20060018009Abstract: An apparatus for optical amplification that imparts to a narrow band optical amplifier, specifically an Erbium dope fiber amplifier (EDFA), gain properties found in wide band optical amplifiers. In one preferred embodiment, the apparatus comprises an EDFA and an externally attachable (to the EDFA) module that includes a single un-pumped Erbium doped fiber (EDF) connected to a gain flattening filter (GFF). The GFF may be internal or external to the module. In another embodiment, the apparatus comprises an EDFA and an externally attachable module having a plurality of un-doped EDFs with different lengths, switchably connectable to the GFF and the EDFA to provide the required wide-band gain properties.Type: ApplicationFiled: February 28, 2005Publication date: January 26, 2006Inventors: Uri Ghera, Alex Shlifer, David Menashe
-
Publication number: 20030185531Abstract: A limited mode dispersion compensating optical fiber supporting at least one high order spatial mode comprising a plurality of core areas. The refractive index profile of the fiber are selected to result in an optical waveguide providing in the LP02 mode dispersion more negative than −300 ps/nm/km at a representative wavelength within an operative waveband, a projected zero dispersion (PZD) less more than 75 nm less than the representative wavelength and third order dispersion less than 2% over the operative waveband. Third order dispersion is defined as the maximum deviation from a best line fit for dispersion divided the best fit dispersion at the representative wavelength, with the best fit line being chosen to minimize the maximum deviation. In one embodiment the PZD lies between 1340 nm and 1420 nm, and in another embodiment the PZD lies between 1420 nm and 1475 nm.Type: ApplicationFiled: January 9, 2003Publication date: October 2, 2003Inventors: Michael Lysiansky, David Menashe
-
Publication number: 20020164140Abstract: A family of fiber profiles is disclosed which exhibit only three well guided modes in the operative “band”. The reduction in the number of modes is accomplished with a change in the refractive index in the core area. The change in refractive index in the core area changes the order of the appearance of the modes, thus leading to fewer guided modes, and less MPI. In one embodiment the refractive index ring comprises an area of depressed refractive index, and the null energy point of one of the guided modes is found therein. In another embodiment, the change in the refractive index in the core is located coincidentally with the null point of a desired mode. In some embodiments negative dispersion on the order of −400 ps/nm/km is experienced, while MPI is minimized. In another embodiment the fiber profile is further characterized by a negative slope suitable for compensating a link of transmission fiber.Type: ApplicationFiled: May 1, 2002Publication date: November 7, 2002Inventors: Michael Lysiansky, David Menashe, Yochay Danziger