| 61. |
- Czegledi, Cristian Bogdan, 1988, et al.
(författare)
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Modified Digital Backpropagation Accounting for Polarization-Mode Dispersion
- 2017
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Ingår i: Optical Fiber Communication Conference. - 9781943580231
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Konferensbidrag (refereegranskat)abstract
- We propose a modified DBP algorithm accounting for PMD. The accumulated PMD at the receiver is factorized into several PMD sections, and inserted into the DBP routine to distributively compensate for PMD, outperforming the conventional approach by 1.1 dB in SNR.
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| 62. |
- Czegledi, Cristian Bogdan, 1988, et al.
(författare)
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Modulation Format Independent Joint Polarization and Phase Tracking for Coherent Receivers
- 2016
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Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 13:14, s. 3354-3364
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Tidskriftsartikel (refereegranskat)abstract
- © 1983-2012 IEEE. The state of polarization and the carrier phase drift dynamically during transmission in a random fashion in coherent optical fiber communications. The typical digital signal processing solution to mitigate these impairments consists of two separate blocks that track each phenomenon independently. Such algorithms have been developed without taking into account mathematical models describing the impairments. We study a blind, model-based tracking algorithm to compensate for these impairments. The algorithm dynamically recovers the carrier phase and state of polarization jointly for an arbitrary modulation format. Simulation results show the effectiveness of the proposed algorithm, having a fast convergence rate and an excellent tolerance to phase noise and dynamic drift of the polarization at low complexity, which make the algorithm a strong candidate for future optical systems.
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| 63. |
- Czegledi, Cristian Bogdan, 1988, et al.
(författare)
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Polarization Drift Channel Model for Coherent Fibre-Optic Systems
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 6, s. 21217-
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Tidskriftsartikel (refereegranskat)abstract
- A theoretical framework is introduced to model the dynamical changes of the state of polarization during transmission in coherent fibre-optic systems. The model generalizes the one-dimensional phase noise random walk to higher dimensions, accounting for random polarization drifts, emulating a random walk on the Poincare sphere, which has been successfully verified using experimental data. The model is described in the Jones, Stokes and real four-dimensional formalisms, and the mapping between them is derived. Such a model will be increasingly important in simulating and optimizing future systems, where polarization-multiplexed transmission and sophisticated digital signal processing will be natural parts. The proposed polarization drift model is the first of its kind as prior work either models polarization drift as a deterministic process or focuses on polarization-mode dispersion in systems where the state of polarization does not affect the receiver performance. We expect the model to be useful in a wide-range of photonics applications where stochastic polarization fluctuation is an issue.
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| 64. |
- Czegledi, Cristian Bogdan, 1988, et al.
(författare)
-
Polarization-Mode Dispersion Aware Digital Backpropagation
- 2016
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Ingår i: 42nd European Conference on Optical Communication, ECOC 2016; Dusseldorf; Germany; 18 September 2016 through 22 September 2016. - 9783800742745 ; , s. 1091-1093
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Konferensbidrag (refereegranskat)abstract
- We study a modified DBP algorithm that accounts for PMD. Based on the accumulated PMD at the receiver, the algorithm distributively compensates for PMD in the reverse propagation and outperforms the conventional approach by up to 2.1 dB.
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| 65. |
- Czegledi, Cristian Bogdan, 1988, et al.
(författare)
-
Symbol-by-Symbol Joint Polarization and Phase Tracking in Coherent Receivers
- 2015
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Ingår i: Optical Fiber Communication Conference, OFC 2015; Los Angeles Convention CenterLos Angeles; United States; 22 March 2015 through 26 March 2015. - Washington, D.C. : OSA. - 9781557529374 - 9781557529374
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Konferensbidrag (refereegranskat)abstract
- An analytical model to describe the combined drift of the state of polarization and absolute phase is presented. To compensate for this drift, a novel, modulation format independent algorithm is proposed, which outperforms state-of-the-art algorithms.
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| 66. |
- Czegledi, Cristian Bogdan, 1988, et al.
(författare)
-
Temporal stochastic channel model for absolute polarization state and polarization-mode dispersion
- 2017
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Ingår i: 2017 Optical Fiber Communications Conference and Exhibition, OFC 2017 - Proceedings. - 2162-2701. - 9781943580231
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Konferensbidrag (refereegranskat)abstract
- We propose and validate a discrete-time channel model for the temporal drift of the absolute polarization state and polarization-mode dispersion for coherent fiber optic systems. The model can be used in simulations to test and develop DSP for coherent receivers.
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| 67. |
- Dadap, J. I., et al.
(författare)
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Focus issue introduction: Nonlinear optics 2013
- 2013
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Ingår i: Optics Express. - : The Optical Society. - 1094-4087 .- 1094-4087. ; 21:25, s. 31176-31178
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Tidskriftsartikel (refereegranskat)abstract
- Nonlinear Optics has continued to develop over the last few years at an extremely fast pace, with significant advances being reported in nonlinear optical metamaterials, optical signal processing, quantum optics, nonlinear optics at subwavelength scale, and biophotonics. These exciting new developments have generated significant potential for a broad spectrum of technological applications in which nonlinear-optical processes play a central role. (C) 2013 Optical Society of America
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| 68. |
- Deriushkina, Ekaterina, 1992, et al.
(författare)
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Characterisation of a Coupled-Core Fiber Using Dual-Comb Swept-Wavelength Interferometry
- 2021
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Ingår i: 2021 European Conference on Optical Communication, ECOC 2021.
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Konferensbidrag (refereegranskat)abstract
- We present a measurement of the transfer matrix of a coupled three-core fiber using a novel combination of swept-wavelength interferometry and dual-comb spectroscopy capable of measuring 1 THz bandwidth with a frequency resolution of 50 kHz with only a 25 GHz laser sweep.
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| 69. |
- Deriushkina, Ekaterina, 1992, et al.
(författare)
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Dual-Comb Swept-Wavelength Interferometry : Theory and Experiment
- 2022
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Ingår i: Journal of Lightwave Technology. - : Institute of Electrical and Electronics Engineers Inc.. - 0733-8724 .- 1558-2213. ; 40:19, s. 6508-6516
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Tidskriftsartikel (refereegranskat)abstract
- Much efforts have been put to elaborate and improve different high precision measurement schemes for characterization of advanced photonic devices and optical fibers with increasing bandwidth requirements. In light of this, swept-wavelength interferometry and dual-comb spectroscopy have been extensively applied in characterization procedures. In this paper we present in detail an experimental scheme that combines these two techniques and overcomes their limitations by using a tunable laser source in order to sweep over the frequency comb spacing and capture all intermediate frequencies. We demonstrate full-field broadband measurements over 1.25 THz comb bandwidth with increased frequency resolution, which can be performed in only 5 ms sweep. We also show that the nonlinearity of the laser sweep can be removed without an auxiliary interferometer in the setup.
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| 70. |
- Deriushkina, Ekaterina, 1992, et al.
(författare)
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Modeling of 3-Coupled-Core Fiber: Comparison Between Scalar and Vector Random Coupling Models
- 2024
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Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 42:2, s. 793-801
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Tidskriftsartikel (refereegranskat)abstract
- Simple, fast and accurate channel models can assist not only in a process of manufacturing of novel multi-core fibers, but also in a communication link design, providing a convenient way to investigate different properties of fibers that could be appealing for transmission. Models for coupled-core fibers are in a great demand since this type of the fiber provides advantages for data transmission, e.g. by reducing the effects of modal dispersion and fiber nonlinearity. In this work we present a comparative study of key features in a three coupled-core fiber (3CCF) for scalar and vector random coupling models. Supermodes and their group delays in an unperturbed 3CCF with polarization mode mixing are comprehensively analyzed for the first time. It is shown that birefringence does not impact significantly the group delay values but it may affect the mode mixing. The intensity impulse response and its RMS width were then investigated in a 3CCF with perturbations and compared for two types of models. The shape of the averaged intensity impulse response is found to be very similar for two models and retained for various input polarization states, while in the absence of averaging, the shape of the impulse response strongly depends on the input state of polarization. We show that the calculated RMS widths of the intensity impulse response agree well with theoretical values, as well as between scalar and vector cases.
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