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公开(公告)号：JPH09186658A
公开(公告)日：1997-07-15
申请号：JP32924896
申请日：1996-12-10
Applicant: LUCENT TECHNOLOGIES INC
Inventor： FATEHI MOHAMMAD T , HEISMANN FRED LUDWIG
Abstract: PROBLEM TO BE SOLVED: To monitor a signal routing of a multiple wavelength optical network by allowing the system to be made up of an output difference element connecting to an inverting input, a noninverting input and a dithering element, a dither signal generator and a feedback element giving input of a signal relating to an output of the dithering element to the inverting input of the difference element. SOLUTION: An intensity modulator 2 is arranged in series with an optical carrier 4 modulated by an information signal. A differential amplifier circuit 7 has an inverting input, a noninverting input and an output connecting to an input of the intensity modulator 2 as a dither element and is made up of an adder 6 and an operational amplifier conditioner 8. A signal generator 10 generates a desired identifier tone and overhead information to be added to a modulation optical carrier. Furthermore, the signal generator 10 connects to the noninverting input of the differential amplifier 7. Furthermore, the feedback element is used to generate a signal relating to an output of the intensity modulator 2 based on a modulation index of the identifier tone.
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公开(公告)号：JPH11196046A
公开(公告)日：1999-07-21
申请号：JP26073898
申请日：1998-09-16
Applicant: LUCENT TECHNOLOGIES INC
Inventor： FISHMAN DANIEL A , HEISMANN FRED LUDWIG , WILSON DAVID L
Abstract: PROBLEM TO BE SOLVED: To provide a device which can automatically fit a primary polarization mode dispersion(PMD) level by producing a control signal proportional to the total value of the differential optical time delay of the optical signal occurring at the output part of a variable birefringence element via an optical signal analyzer and controlling the differential time delay value, which is generated for the control of selecting a specific orthogonal polarization state by means of the control signal. SOLUTION: Automatic fitting is attained to a PMD level, via the differential time delay of a variable differential time delay line 50 and the supply of a feedback signal, that controls the polarization transformation of a polarization transformer 30. Some of signals which are outputted from a compensation device 25 are supplied to a path 87 which reaches a fast photodetection device 55 via an optical tap 85, and other signals are supplied to a path 86 reaching a receiver 90. The device 55 converts the fast digital information signal modulated on an optical carrier signal into an electric signal. The electric signal is amplified by an amplifier 60 and sent to an electrical distortion analyzer 70 which measures the distortion of the amplified optical current and coverts the amplified result into a voltage that is proportional to the measured distortion.
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公开(公告)号：CA2449694C
公开(公告)日：2004-08-31
申请号：CA2449694
申请日：2000-12-06
Applicant: LUCENT TECHNOLOGIES INC
Inventor： FISHMAN DANIEL A , HEISMANN FRED LUDWIG , WILSON DAVID L
IPC: H04B10/07 , G01R23/20 , H04B10/2507 , H04B10/08 , H04B10/18
Abstract: The present invention relates to a distortion analyzer that is comprised of a converter for converting a signal outputted by optical apparatus into an electrical signal and splitting the converted signal into a plurality of signals. The analyzer also includes first, second, and third analyzer sections for receiving respective ones of the plurality of signals such that the first analyzer section operates to pass the entire spectrum of the outputted signal, the second section operates to pass only that portion of the entire spectrum that is below a predetermined frequency and the third section operates to pass a predetermined band of the entire spectrum. A summing unit is provided for summing the outputs of the first and second sections and subtracting the output of the third section from the summed result to generate a distortion indicator and supplying the distortion indicator to the optical apparatus.
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公开(公告)号：CA2449694A1
公开(公告)日：2001-06-16
申请号：CA2449694
申请日：2000-12-06
Applicant: LUCENT TECHNOLOGIES INC , HATCH LTD
Inventor： HEISMANN FRED LUDWIG , FISHMAN DANIEL A , WILSON DAVID L
IPC: H04B10/07 , G01R23/20 , H04B10/2507 , H04B10/08 , H04B10/18
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公开(公告)号：CA2200236C
公开(公告)日：2000-09-19
申请号：CA2200236
申请日：1997-03-18
Applicant: LUCENT TECHNOLOGIES INC , MYERS JOEL S
Inventor： HEISMANN FRED LUDWIG , SMITH ROBERT W
Abstract: Two separate electrooptic phase modulators are used in a modified Mach-Zehnder interferometer to vary the absolute and relative optical phases of two orthogonally polarized modes of an input signal independently of each other. A conventional Y-branch splitter on lithium niobate splits the input signal equally into the two waveguide phase modulators and an external polarization splitter recombines the two phase modulated signals in orthogonal polarization states. The polarization in the interferometer is maintained by connecting the outputs of the two phase modulators to polarization maintaining fibers. An alternate embodiment of the present invention uses an additional 3-dB directional coupler to mix the two phase modulated signals before they are combined in orthogonal polarization states.
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Patent Agency Ranking
公开(公告)号：NO984185A
公开(公告)日：1999-03-17
申请号：NO984185
申请日：1998-09-11
Applicant: LUCENT TECHNOLOGIES INC
Inventor： FISCHMAN DANIEL A , HEISMANN FRED LUDWIG , WILSON DAVID L
CPC classification number: H04B10/2569
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公开(公告)号：CA2327709C
公开(公告)日：2004-10-19
申请号：CA2327709
申请日：2000-12-06
Applicant: LUCENT TECHNOLOGIES INC
Inventor： FISHMAN DANIEL A , HEISMANN FRED LUDWIG , WILSON DAVID L
Abstract: The effect of polarization mode dispersion that an optical signal experience s as it propagates through an optical transmission fiber is compensated for at a receiver using a birefringent compensator, in which a distortion analyzer repeatedly examines the signal outputted by the compensator and causes the compensator to reduce the effect of such polarization mode dispersion based on the results of such examination.
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公开(公告)号：CA2450499C
公开(公告)日：2004-08-10
申请号：CA2450499
申请日：2000-12-06
Applicant: LUCENT TECHNOLOGIES INC
Inventor： WILSON DAVID L , HEISMANN FRED LUDWIG , FISHMAN DANIEL A
IPC: H04B10/07 , G01R23/20 , H04B10/2507 , H04B10/08 , H04B10/18
Abstract: The present invention relates to a distortion analyzer. The distortion analyzer is comprised of a converter for converting a signal outputted by optical apparatus into an electrical signal. A receiver is provided for converting the electrical signal into AC and DC components, for splitting the AC component signal into a plurality of signals, and for supplying the AC component signals to respective sections of a distortion analyzer. A squaring unit is provided for squaring the vague of the DC component. A divider divides the output from the distortion analyzer by the value of the squared signal and supplies the resulting quotient signal as a distortion indicator to the optical apparatus. The optical apparatus is responsive to receipt of the distortion indicator, and changes the level of the outputted signal until the distortion indicator reaches a predetermined state.
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9.发明专利
公开(公告)号：CA2245303A1
公开(公告)日：1999-03-16
申请号：CA2245303
申请日：1998-08-19
Applicant: LUCENT TECHNOLOGIES INC
Inventor： FISHMAN DANIEL A , HEISMANN FRED LUDWIG , WILSON DAVID L
Abstract: The effect of polarization mode dispersion that an optical signal experiences as it propagates through an optical transmission fiber is compensated for at a receiver using a birefringent compensator, in which the compensator automatically and adaptively generates a level of differential time delay that substantially equals the differential time delay that the optical signal experiences, but of different sign, and, therefore, essentially cancels out the undesired delay.
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公开(公告)号：CA2200236A1
公开(公告)日：1997-10-26
申请号：CA2200236
申请日：1997-03-18
Applicant: LUCENT TECHNOLOGIES INC
Inventor： HEISMANN FRED LUDWIG , SMITH ROBERT W
Abstract: Two separate electrooptic phase modulators are used in a modified Mach-Zehnder interferometer to vary the absolute and relative optical phases of two orthogonally polarized modes of an input signal independently of each other. A conventional Y-branch splitter on lithium niobate splits the input signal equally into the two waveguide phase modulators and an external polarization splitter recombines the two phase modulated signals in orthogonal polarization states. The polarization in the interferometer is maintained by connecting the outputs of the two phase modulators to polarization maintaining fibers. An alternate embodiment of the present invention uses an additional 3-dB directional coupler to mix the two phase modulated signals before they are combined in orthogonal polarization states.
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