Showing papers on "Polarization mode dispersion published in 2000"
TL;DR: This paper reviews the fundamental concepts and basic theory of polarization mode dispersion in optical fibers and introduces a unified notation and methodology to link the various views and concepts in Jones space and Stokes space.
Abstract: This paper reviews the fundamental concepts and basic theory of polarization mode dispersion (PMD) in optical fibers. It introduces a unified notation and methodology to link the various views and concepts in Jones space and Stokes space. The discussion includes the relation between Jones vectors and Stokes vectors, rotation matrices, the definition and representation of PMD vectors, the laws of infinitesimal rotation, and the rules for PMD vector concatenation.
787 citations
TL;DR: In this article, the authors reported the most detailed long-term measurement of polarization mode dispersion (PMD) made to date, and quantified the temporal drift by computing the autocorrelation function of the PMD-vector analytically, both with respect to wavelength and to drift time.
Abstract: We report the most detailed long-term measurement of polarization mode dispersion (PMD) made to date. We measured two separate fibers under the same time period, which makes it possible to compare the drift properties of two similar fibers in the same environment. The measured Jones matrices suffers from both random and systematic errors, a generic problem which we discuss in detail and solve. The results confirmed the well-known statistical properties of the PMD-vector. Furthermore, the drift averaged over wavelength is very well (96%) correlated between the two fibers. We finally quantified the temporal drift by computing the autocorrelation function of the PMD-vector analytically, both with respect to wavelength and to drift time. The analytical theory shows good agreement with the measurements.
212 citations
TL;DR: In this paper, the combined effects of polarization-mode dispersion (PMD) and polarization dependent losses (PDL) in optical fiber networks were investigated and it was shown that the combination of PMD and PDL may lead to anomalous dispersion, which is not correctly described by a direct application of the Jones matrix eigenanalysis (JME) method.
Abstract: We review the formalism required to investigate the combined effects of polarization-mode dispersion (PMD) and polarization dependent losses (PDL) in optical fiber networks. The combination of PMD and PDL may lead to anomalous dispersion, which is not correctly described by a direct application of the Jones matrix eigenanalysis (JME) method. This calls for a careful assessment of PMD measurement methods in the presence of PDL. We also present a theoretical analysis of distortions in analog transmissions, and computer simulations of digital transmissions. These show that distributed PDL increases the power penalty of the transmission more than lumped PDL at the end of the channel.
170 citations
TL;DR: The measurements are in good agreement with theoretical predictions and show, for what the authors believe is the first time, that the components of the local birefringence vector are Gaussian random variables.
Abstract: The statistical properties of the random birefringence that affects long single-mode fibers are experimentally evaluated by means of a polarization-sensitive optical time-domain reflectometry. The measurements are in good agreement with theoretical predictions and show, for what we believe is the first time, that the components of the local birefringence vector are Gaussian random variables.
153 citations
TL;DR: The proposed measurement technique is based on a polarization-sensitive analysis of the backscattered signal and allows one to calculate the correlation length of the random birefringence affecting the fiber.
Abstract: Experimental results of measurement of the beat length and the differential group delay of several types of long single-mode fiber are presented. The proposed measurement technique is based on a polarization-sensitive analysis of the backscattered signal and allows one to calculate the correlation length of the random birefringence affecting the fiber.
152 citations
TL;DR: In this paper, experiments and simulations of second-order polarization mode dispersion components in optical fibers with emphasis on polarization-dependent chromatic dispersion (PCD) were described and compared.
Abstract: We describe experiments and simulation of second-order polarization mode dispersion (PMD) components in optical fibers with emphasis on polarization-dependent chromatic dispersion (PCD). Excellent agreement is found in comparisons of experimental, simulated, and theoretical probability densities. To our knowledge, these are the first such comparisons for the second-order PMD magnitude and the PCD.
113 citations
TL;DR: In this article, an adaptive polarization-mode dispersion (PMD) compensation system was developed to cancel the effects of first-order PMD by producing a complementary PMD vector in the receiver.
Abstract: An adaptive polarization-mode dispersion (PMD) compensation system has been developed to cancel the effects of first-order PMD by producing a complementary PMD vector in the receiver. Control parameters for the PMD compensation system comprised of a polarization controller and a PMD emulator are derived from the nonreturn-to-zero (NRZ) signal in the channel to be compensated. Estimates of the link's differential group delay (DGD) and principal states of polarization (PSPs) based on this signal are reliable when the signal power is equally split between the link's two PSP's; however this condition cannot be assumed. To meet this requirement, we scramble the state of polarization (SOP) of the input signal at a rate much greater than the response time of the PMD monitor signal so that each sample represents many different SOP alignments. This approach allows the effective cancellation of the first-order PMD effects within an optical fiber channel.
101 citations
TL;DR: In this article, a 640-Gbit/s optical time division multiplexed signal was successfully transmitted over a 92-km zero-dispersion-flattened transmission line.
Abstract: A 640-Gbit/s optical time division multiplexed signal was successfully transmitted over a 92-km zero-dispersion-flattened transmission line. The transmission line consisted of single-mode fiber, dispersion-shifted fiber, and reverse dispersion fiber. By using reverse dispersion fiber instead of dispersion slope compensation fiber, we were able to increase the transmission distance from 63 to 92 km because reverse dispersion fiber has less polarization mode dispersion and a flatter dispersion profile.
97 citations
Patent•
11 Oct 2000
TL;DR: In this paper, a dispersion compensator was proposed to compensate for the unwanted chromatic dispersion, dispersion slope, and polarization mode dispersion in a VIPA-based system.
Abstract: The present invention provides a dispersion compensator which utilizes a Virtually Imaged Phased Array (VIPA), gratings, and birefringent wedges to moderate chromatic dispersion, dispersion slope and polarization mode dispersion, and a method and system for testing such a dispersion compensator. The dispersion compensator in accordance with the present invention propagates the composite optical signal in a forward direction; separates the wavelengths in the band of wavelengths in each of the plurality of channels, where each of the wavelengths in the band is spatially distinguishable from the other wavelengths in the band; spatially separates each band of wavelengths in the plurality of channels; spatially separates each wavelength of each separated band of wavelengths into a plurality of polarized rays; and reflects the plurality of polarized rays toward a return direction, where dispersion is added to the reflected plurality of polarized rays such that the unwanted chromatic dispersion, dispersion slope, and PMD are compensated. The dispersion compensator provides simultaneous tunable compensation of these various dispersions utilizing a single apparatus. A system which utilizes the compensator is thus cost effective to manufacture. Systems may be provides which determines the operating and performance parameters for the compensator, and measures the spectrum outputted by the compensator.
92 citations
Patent•
15 Sep 2000
TL;DR: In this paper, a variable delay device is proposed to correct for polarization mode dispersion in a signal transmitted over an optical communications system, which uses a plurality of polarization rotators and delay elements aligned in series and alternating with one another.
Abstract: A variable delay device of the type used to correct for polarization mode dispersion in a signal transmitted over an optical communications system. In an exemplary embodiment, the variable delay device uses a plurality of polarization rotators and delay elements aligned in series and alternating with one another. The polarization rotators map the fast polarization mode component of the incoming optical signal to the slow axes of one or more delay elements, to achieve a desired pattern of relative incremental delays which total the initial differential delay being compensated. The delay elements may have uniform or non-uniform incremental delay values, and the polarization rotators may be selectively actuated to achieve the desired pattern of delay values corresponding to the intended total delay. Examples of suitable delay devices include waveguides having relatively high differential group delay characteristics associated with two orthogonal axes compared with conventional single-mode transmission fiber, and examples of suitable polarization rotators include twisted nematic liquid crystal (TNLC) or ferroelectric liquid crystal (FLC) cells which rotate the polarization mode components of the optical signal by 90° when actuated.
81 citations
TL;DR: In this article, the authors derive the signal bandwidth below which the first-order approximation of the principal states of polarization is valid, and show that this bandwidth depends only on the mean value of the differential group delay.
Abstract: Using the retarded plate model, we derive the correlations and the mean-square values of all orders of polarization mode dispersion (PMD) as well as the autocorrelation function of the PMD vector. Our results provide the signal bandwidth below which the first-order approximation of the principal states of polarization is valid. We show that this bandwidth depends only on the mean value of the differential group delay. Our theoretical results are supported by simulations and experiments.
TL;DR: In this article, the random coupling-length basis was used in the numerical simulation of single-mode fibers (SMF's) with the coarse step method, and a single set of coupling lengths, angles and phases accounts for both, the Maxwellian statistics and the nonperiodical differential group delay spectral dependence in agreement with experimental observations.
Abstract: The random coupling-length basis was used in the numerical simulation of single-mode fibers (SMF's) with the coarse step method. We show that a single set of coupling lengths, angles and phases accounts for both, the Maxwellian statistics and the nonperiodical differential group delay spectral dependence in agreement with experimental observations. An SMF and a polarization mode dispersion (PR ID) emulator were both measured and simulated. The comparison between the experimental results and numerical simulations shows that the random coupling-lengths mathematical model and the emulator device provide good descriptions either for the first-order PMD statistics or second-order PMD, being powerful tools for the simulation of signal distortion.
TL;DR: In this paper, a polarization mode dispersion compensator for the rotation of the principal states with frequency is proposed. But the compensator requires only two control elements more than existing first-order compensators, i.e., the position of one polarization controller and a single delay.
Abstract: We present a polarization mode dispersion compensator for the rotation of the principal states with frequency. This compensator requires only two control elements more than existing first-order compensators. These are the position of one polarization controller and the setting of a single delay. With the proposed scheme, compensation for first order can be decoupled from the compensation for higher orders and controlled independently. The effect of the compensator on signal transmission is evaluated with extensive numerical simulations.
TL;DR: In this article, a theoretical basis of polarization mode dispersion (PMD) equalizers based on the operator representation of PMD using Taylor's expansion is introduced, and two types of configuration of the PMD equalizers are derived as the inverse of diagonalization operators and delay time difference compensation.
Abstract: We introduce a theoretical basis of polarization mode dispersion (PMD) equalizers based on the operator representation of PMD using Taylor's expansion. The two types of configuration of PMD equalizers are derived as the inverse of diagonalization operators and delay time difference compensation. One is a type using physical rotation of quarter wave phase plates. The other is a type using variable phase shifters suitable for PLC integration. Waveform comparison algorithm was simulated to show the existence of multiple equivalent optimum points due to the symmetry and periodicity of optical circuits. The second order PMD equalization is discussed briefly on the case of cascading the first and the second PMD equalizing circuits with two different polarization state converters.
TL;DR: A Jones matrix is constructed for a fiber that exhibits first- and second-order polarization mode dispersion (PMD) and is a correction to the Bruyère model.
Abstract: A Jones matrix is constructed for a fiber that exhibits first- and second-order polarization mode dispersion (PMD). It permits the modeling of pulse transmission for fibers whose PMD vectors have been measured or whose statistics have been determined by established PMD theory. The central portion of our model is a correction to the Bruyere model.
30 Nov 2000
TL;DR: In this paper, the authors investigate a new technique to realistically emulate polarization mode dispersion and demonstrate that 15 sections of polarization-maintaining fiber with randomly rotatable connections emulates an almost ideal Maxwellian differential group delay (DGD) distribution.
Abstract: We investigate a new technique to realistically emulate polarization mode dispersion. We demonstrate that 15 sections of polarization-maintaining fiber with randomly rotatable connections emulates an almost ideal Maxwellian differential group delay (DGD) distribution, whereas fixed connections is inadequate.
TL;DR: It is shown that the correlation bandwidth of the differential group delay is comparable with that of the orientation of the PMD vector, and all the most general statistical properties of polarization mode dispersion in long fibers are uniquely determined by the mean DGD.
Abstract: We study the frequency autocorrelation of the differential group delay (DGD) in fibers with polarization mode dispersion (PMD). We show that the correlation bandwidth of the DGD is comparable with that of the orientation of the PMD vector. Furthermore, we show that all the most general statistical properties of polarization mode dispersion in long fibers are uniquely determined by the mean DGD. An estimate of the accuracy of measurements in which the mean DGD is extracted by frequency averaging in a single fiber is obtained as a function of the measured bandwidth.
TL;DR: In this article, exact analytical expressions for the expected pulse broadening in a fiber-optic transmission system suffering from both first and higher order polarization mode dispersion (PMD) were derived.
Abstract: We derive exact analytical expressions for the expected pulse broadening in a fiber-optic transmission system suffering from both first- and higher order polarization mode dispersion (PMD). Furthermore, we quantify the influence of two simple PMD-compensation techniques.
07 Feb 2000
TL;DR: In this paper, a single chip eye opening monitor (EOM) is used as part of a signal processing unit for TDM transmissions on long haul fiber links, which is not only limited by the speed of electronic components but also by problems like fiber dispersion, polarization mode dispersion and fiber nonlinearities.
Abstract: The use of high bit rates for TDM transmissions on long haul fiber links is not only limited by the speed of electronic components but also by problems like fiber dispersion, polarization mode dispersion and fiber nonlinearities, especially if an installed standard fiber is used. An approach to alleviate these problems is the use of electronic signal-processing functions and advanced modulation schemes. This single chip eye opening monitor (EOM) is for use as part of such a signal processing unit. Apart from the data signal, a regenerated clock of arbitrary phase is needed to generate a dc output voltage proportional to the horizontal eye opening with a response time of <1 ms. The IC, in 50 GHz-f/sub T/ SiGe bipolar technology, covers bit rates from 2 to 12.5 Gb/s and dissipates 4.95 W from -5 V.
TL;DR: In this article, the authors studied the evolution of optical signals in single-mode optical fibers in the presence of polarization-mode dispersion and polarization-dependent losses and obtained general statistical results.
Abstract: We study the evolution of optical signals in single-mode optical fibers in the presence of polarization-mode dispersion and polarization-dependent losses. Two geometric vectors on the Poincare sphere are defined to characterize the effects of polarization-mode dispersion and polarization-dependent losses on the optical field in the fiber. By solving the dynamical equation for these two vectors, several general statistical results are obtained. The practically important weak polarization-dependent-loss situation is discussed in detail.
Patent•
09 Feb 2000TL;DR: In this paper, a nonlinearly chirped fiber grating (1020a) was proposed for achieving tunable dispersion compensation, dispersion slope compensation, polarization mode dispersion, chirp reduction in directly modulated diode lasers, and optical pulse manipulation.
Abstract: A nonlinearly chirped fiber grating (1020a) for achieving tunable dispersion compensation, dispersion slope compensation, polarization mode dispersion, chirp reduction in directly modulated diode lasers, and optical pulse manipulation. A dynamical dispersion compensation mechanism can be implemented in a fiber communication system (1001) based on a such a nonlinearly chirped fiber grating (1020a).
TL;DR: In this paper, beat length and polarization mode dispersion (PMD) measurements performed on installed fibers were performed on three different kinds of fibers: standard step index, dispersion shifted and nonzero dispersion.
Abstract: We present beat length and polarization mode dispersion (PMD) measurements performed on installed fibers. Results regard three different kinds of fibers: standard step index, dispersion shifted and nonzero dispersion (NZD). After a historical comparison with standard differential group delay measurement collected four years ago on the same fibers, we perform a spatial-resolved measurement of the beat length by analyzing the state of polarization of the backscattered field. We compare PMD properties of different fibers and calculate the statistical distribution of the beat length. The differential group delay (DGD) and the beat length statistics depend strongly on fiber type and on fiber position along the link. The influence of the beat length on the DGD is also discussed.
TL;DR: Coherent crosstalk mechanisms induced by polarization mode dispersion in polarization multiplexed fiber transmission are examined by systems experiments, analysis and supporting modeling, and rules of thumb for tolerable crosStalk levels are developed.
Abstract: Coherent crosstalk mechanisms induced by polarization mode dispersion in polarization multiplexed fiber transmission are examined by systems experiments, analysis and supporting modeling. Primary mechanisms include destructive interference, edge effects, and beat effects, leading to pulse distortion and to bit-error-rate penalties. Rules of thumb for tolerable crosstalk levels are developed.
07 Mar 2000
TL;DR: A programmable polarization-mode dispersion emulator was demonstrated in this paper, and a higher-order PMD was systematically generated in a motorized rotating stage with 12 birefringent crystals with 10 ps differential-group delay.
Abstract: A programmable polarization-mode dispersion emulator is demonstrated first and higher-order PMD is systematically generated. Twelve birefringent crystals with 10 ps differential-group-delay apiece are mounted in twelve computer controlled motorized rotating stages.
Patent•
01 Sep 2000TL;DR: In this paper, the authors proposed an optical fiber for compensating chromatic dispersion of a positive chromatic-dispersion optical fiber with an effective area greater than or equal to 12 μm 2 and curvature losses less than 0.05 dB.
Abstract: An optical fiber for compensating chromatic dispersion of a positive chromatic dispersion optical fiber has at a wavelength of 1 550 nm a chromatic dispersion less than −40 ps/(nm.km), a ratio between the chromatic dispersion and the chromatic dispersion slope in the range from 50 nm to 230 nm, an effective area greater than or equal to 12 μm 2 and curvature losses less than or equal to 0.05 dB. It is used for in-line compensation of cumulative chromatic dispersion in a positive chromatic dispersion line fiber. A fiber optic transmission system is also disclosed using a fiber of this kind to compensate the cumulative chromatic dispersion in the line fiber.
Patent•
KDDI1
TL;DR: In this paper, a bandpass filter (BPF) is used to extract a clock component of the signal from an output of a photodetector and a controller controls the polarization converter to adjust the polarization angle of the output light according to the output of the BPF.
Abstract: A signal light from an optical transmission line propagates on a first optical fiber and enters a polarization converter. The polarization converter converts the input light with the given polarization into a linear polarization with a desired angle using two Faraday rotators and a quarter wave plate between them. The output light of the polarization converter propagates on a second optical fiber and enters a polarization beam splitter. The polarization beam splitter splits the light from the second optical fiber into two mutually orthogonal polarization components (e.g. TE and TM components) and outputs either of them (e.g. the TE component) toward a third optical fiber. A portion of the light propagating on the third optical fiber is split by an optical coupler and enters a photodetector. A bandpass filter (BPF) extracts a clock component of the signal from an output of the photodetector. A controller controls the polarization converter to adjust the polarization angle of the output light so as to maximize the output of the BPF according to the output of the BPF.
Patent•
08 Mar 2000
TL;DR: In this article, a dispersion compensating optical transmission line comprises a plurality of optical transmission fibers for transmitting signal light, at least one first dispersion compensated compensator disposed at a first dispensation cycle for compensating an accumulated chromatic dispersion of the signal light.
Abstract: A dispersion compensating optical transmission line comprises a plurality of optical transmission fibers for transmitting signal light, at least one first dispersion compensator disposed at a first dispersion compensating cycle for compensating an accumulated chromatic dispersion of the signal light so that an average chromatic dispersion is equal to a first desired value, and a plurality of second dispersion compensators disposed at a second dispersion compensating cycle shorter than the first dispersion compensating cycle for compensating the accumulated chromatic dispersion of the signal light so that an average chromatic dispersion is equal to a second desired value which absolute value is larger than that of the first desired value.
TL;DR: In this paper, the influence of chromatic dispersion, coupling length, and soliton energy on the soliton robustness to polarization-mode dispersion (PMD) was investigated numerically.
Abstract: The influences of chromatic dispersion, coupling length, and soliton energy on the soliton robustness to polarization-mode dispersion (PMD) are investigated numerically. We find that both chromatic dispersion and soliton energy have significant effects on the soliton robustness to PMD, and by optimizing chromatic dispersion and soliton energy, soliton pulse broadening can be depressed to within 10% even when the differential group delay is about twice the input pulse width. In addition, a recent experimental result on soliton robustness is numerically verified.
07 Mar 2000
TL;DR: In this paper, a 3.3 dB reduction of the power penalty induced by the chromatic dispersion of an 127 km standard single-mode fiber (G.652) has been achieved (BER=10/sup -9/, PRBS 2/sup 23/-1) by processing the detected signal in the receiver with a nonlinear equaliser realized as SiGe integrated circuit.
Abstract: At 10 Gbit/s a 3.3 dB reduction of the power penalty induced by the chromatic dispersion of an 127 km standard single-mode fiber (G.652) has been achieved (BER=10/sup -9/, PRBS 2/sup 23/-1) by processing the detected signal in the receiver with a nonlinear equaliser realized as SiGe integrated circuit.
TL;DR: In this article, the authors numerically demonstrate 160 Gb/s densely dispersion-managed soliton transmission in a single channel over 2000 km in the dispersionflattened fibers in the presence of polarization mode dispersion and of large variation in group-velocity dispersion.
Abstract: We numerically demonstrate 160 Gb/s densely dispersion-managed soliton transmission in a single channel over 2000 km in the dispersion-flattened fibers in the presence of polarization mode dispersion and of large variation in group-velocity dispersion. The best performance is achieved by a proper design of the dispersion profile with possible minimum average dispersion, so that the soliton interactions are minimized.