Patents by Inventor Edgard Goobar
Edgard Goobar 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: 8867579Abstract: A laser device (100) includes a laser (110; 210; 310; 410; 510) in turn including at least one Distributed Bragg Reflector (DBR) section (111), at least one phase section (112) and at least one gain section (113), further including a laser control element (150), a feedback control element (140) and a frequency noise discriminator (130,131), which feedback control element is arranged to feed a variable feedback signal to at least one of the at least one DBR section and the at least one phase section of the laser, so that the output laser frequency is altered in response to a variation in the feedback signal or the combination of respective feedback signals, whereby the feedback signal or combination of respective feedback signals is varied as a function of the detected frequency fluctuation so as to counteract the detected frequency fluctuation.Type: GrantFiled: December 20, 2012Date of Patent: October 21, 2014Assignee: Finisar Sweden ABInventors: Edgard Goobar, Urban Eriksson, Jan-Olof Wesstrom
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Patent number: 7911157Abstract: Device for controlling the current through a PN junction includes a voltage source connected in series to, in order, firstly a controllable current generator having an input connected to the voltage source, an output and a control input, thereafter a measurement resistor connected to the output, and finally a controlled output to which the PN junction is connected. The device further includes a control signal input, a differential amplifier and an integrating device, which includes a balanced integrator. The current through the output of the controllable current generator is proportional to the voltage difference between its input and its control input, and the reference voltage of the integrating device is constituted of the voltage of the voltage source.Type: GrantFiled: March 27, 2008Date of Patent: March 22, 2011Assignee: Syntune ABInventors: Edgard Goobar, Gunnar Forsberg
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Publication number: 20100244925Abstract: Device for controlling the current through a PN junction includes a voltage source connected in series to, in order, firstly a controllable current generator having an input connected to the voltage source, an output and a control input, thereafter a measurement resistor connected to the output, and finally a controlled output to which the PN junction is connected. The device further includes a control signal input, a differential amplifier and an integrating device, which includes a balanced integrator. The current through the output of the controllable current generator is proportional to the voltage difference between its input and its control input, and the reference voltage of the integrating device is constituted of the voltage of the voltage source.Type: ApplicationFiled: March 27, 2008Publication date: September 30, 2010Applicant: SYNTUNE ABInventors: Edgard Goobar, Gunnar Forsberg
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Patent number: 6879437Abstract: An optical amplifier arrangement is provided that includes an amplifier (10) elements for measuring the gain applied to the total input power (21, 31, 40) and a control unit (50) adapted to determine the degree of variation of gain with wavelength, i.e. the gain tilt, on the basis of a measurement of total gain. This is achieved by using a predetermined relationship between the wavelength dependent gain variation and total gain. This relationship is determined on production by measurement of the amplifier or of a batch or class of amplifiers. In this way a precise figure for gain tilt is provided for each amplifier. This may be used to eliminate gain tilt. Alternatively, if the system requirements tolerate limited gain tilt, the figure may be used to monitor the system.Type: GrantFiled: February 20, 2001Date of Patent: April 12, 2005Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Johan Sandell, Edgard Goobar, Sven Wingstrand
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Patent number: 6791745Abstract: An amplifier arrangement includes an optical amplifier (10) with a source of injected power (11) for controlling amplifier gain. A feed forward gain control loop is provided with a weighting arrangement (50) capable of weighting the signal power at selected wavelengths input to the amplifier. In this way non-uniform spectral gain of the amplifier may be compensated for by selecting appropriate weighting factors. Thus the influence of wavelengths having a greater than average impact on the decay rate of the excited population within the amplifier is increased and vice versa. By tailoring the weighting arrangement to the specific class of amplifier utilised, and possibly to a specific amplifier within a class, amplifier gain can be precisely controlled and traffic signal power reliably held at a constant level regardless of link configuration changes.Type: GrantFiled: October 15, 2002Date of Patent: September 14, 2004Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Edgard Goobar, Johan Sandell, Sven Wingstrand
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Patent number: 6714343Abstract: The invention concerns a method and apparatus for determining noise power caused by amplified spontaneous emission in a signal output by an optical amplifier (100). The amplifier is connected downstream of further optical amplifiers or components that generates noise power due to amplified spontaneous emission (ASE). The amplifier is connected to a control channel and receives via this channel information about the proportion of ASE power contained in the amplifier input signal. The amplifier further includes a control unit for calculating the ASE power generated in the amplifier, for example using a predetermined relationship between the gain of an amplifier and the generated amplified spontaneous emission (ASE). The ASE power in the amplifier output signal is then determined as the sum of the generated ASE power and the power resulting from propagated ASE. The determined target output power can be used to stabilise the amplifier output.Type: GrantFiled: October 8, 2002Date of Patent: March 30, 2004Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Edgard Goobar, Johan Sandell, Sven Wingstrand
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Publication number: 20030147125Abstract: An optical amplifier arrangement is provided that includes an amplifier (10) elements for measuring the gain applied to the total input power (21, 31, 40) and a control unit (50) adapted to determine the degree of variation of gain with wavelength. i.e. the gain tilt, on the basis of a measurement of total gain. This is achieved by using a predetermined relationship between the wavelength dependent gain variation and total gain. This relationship is determined on production by measurement of the amplifier or of a batch or class of amplifiers. In this way a precise figure for gain tilt is provided for each amplifier. This may be used to eliminate gain tilt. Alternatively, if the system requirements tolerate limited gain tilt, the figure may be used to monitor the system.Type: ApplicationFiled: December 30, 2002Publication date: August 7, 2003Inventors: Johan Sandell, Edgard Goobar, Sven Wingstrand
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Publication number: 20030117696Abstract: The invention concerns a method and apparatus for determining noise power caused by amplified spontaneous emission in a signal output by an optical amplifier (100). The amplifier is connected downstream of further optical amplifiers or components that generates noise power due to amplified spontaneous emission (ASE). The amplifier is connected to a control channel and receives via this channel information about the proportion of ASE power contained in the amplifier input signal. The amplifier further includes a control unit for calculating the ASE power generated in the amplifier, for example using a predetermined relationship between the gain of an amplifier and the generated amplified spontaneous emission (ASE). The ASE power in the amplifier output signal is then determined as the sum of the generated ASE power and the power resulting from propagated ASE.Type: ApplicationFiled: October 8, 2002Publication date: June 26, 2003Inventors: Edgard Goobar, Johan Sandell, Sven Wingstrand
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Publication number: 20030067642Abstract: Embodiments of the present invention provide for ringing and inter-symbol interference reduction in optical communications. In one embodiment of the present invention, the rise time of the signal is longer than the fall time of the signal. The resulting asymmetrical driver pulse is sent to the laser. The resulting overshoot, ringing, undershoot and chirp of the output from the laser are greatly reduced. As a result, the eye is approximately symmetrical and is less closed.Type: ApplicationFiled: October 9, 2001Publication date: April 10, 2003Inventors: Lars-Gote Svenson, Edgard Goobar, Krister Frojdh
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Publication number: 20030053200Abstract: An amplifier arrangement includes an optical amplifier (10) with a source of injected power (11) for controlling amplifier gain. A feed forward gain control loop is provided with a weighting arrangement (50) capable of weighting the signal power at selected wavelengths input to the amplifier. In this way non-uniform spectral gain of the amplifier may be compensated for by selecting appropriate weighting factors. Thus the influence of wavelengths having a greater than average impact on the decay rate of the excited population within the amplifier is increased and vice versa. By tailoring the weighting arrangement to the specific class of amplifier utilised, and possibly to a specific amplifier within a class, amplifier gain can be precisely controlled and traffic signal power reliably held at a constant level regardless of link configuration changes.Type: ApplicationFiled: October 15, 2002Publication date: March 20, 2003Inventors: Edgard Goobar, Johan Sandell, Sven Wingstrand