| 201. |
- Karlsson, Magnus, 1967
(författare)
-
Probability density functions of the differential group delay in optical fiber communication systems
- 2001
-
Ingår i: Journal of Lightwave Technology. - : Institute of Electrical and Electronics Engineers (IEEE). - 0733-8724 .- 1558-2213. ; 19:3, s. 324-331
-
Tidskriftsartikel (refereegranskat)abstract
- Fiber communication systems limited by polarization-mode dispersion (PMD) are usually analyzed using statistics. The probability density function (pdf) of the differential group delay (DGD) is then crucial to know. There are cases for which the commonly used Maxwellian pdf is only approximate, e.g., PMD emulators, or systems with components having single components with large deterministic PMD. Those cases are discussed in this paper, and their pdfs are derived. To do this, we present a very general theory that allows for the derivation of the pdf for almost any birefringent transmission line. As a side result, we are able to prove that the square-sum concatenation formula is valid in almost every case of interest, even if the pdf is far from Maxwellian.
|
|
| 202. |
- Karlsson, Magnus, 1967, et al.
(författare)
-
Quaternion approach to PMD and PDL phenomena in optical fiber systems
- 2004
-
Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 22:4, s. 1137-1146
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we introduce the concept of quaternions (which is a generalization of the complex numbers) and quaternion calculus and demonstrate how this theory may be used to simplify the treatment of polarization phenomena in optical fibers. We apply quaternion calculus to two examples: 1) the description of polarization-dependent loss (PDL) elements and concatenation of such and 2) the description of pulse dynamics and broadening in transmission lines with both polarization-mode dispersion (PMD) and PDL. Finally we present some novel results from the investigation of pulse broadening in a simple system comprising a PMD element, followed by a perfect polarizer.
|
|
| 203. |
- Karlsson, Magnus, 1967, et al.
(författare)
-
Soliton-like pulses governed by fourth order dispersion in optical fibers
- 1994
-
Ingår i: Optics Communications. - : Elsevier BV. - 0030-4018. ; 104:4-6, s. 303-307
-
Tidskriftsartikel (refereegranskat)abstract
- The properties of pulse propagation in a nonlinear fiber including negative fourth order dispersion added to anomalous second order dispersion are analyzed numerically and analytically. An exact localized analytical solution is presented, and using an approximate variational method, an entire family of stationary approximate solutions is also obtained. These solutions are found to be in excellent agreement with numerical simulations.
|
|
| 204. |
- Karlsson, Magnus, 1967, et al.
(författare)
-
Soliton Stability in PMD Perturbed Transmission Systems
- 1998
-
Ingår i: New Trends in Optical Soliton Transmission Systems. - Dordrecht : Springer Netherlands. - 9789401151412 ; , s. 25-37
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a detailed investigation of how solitons broaden in the presence of polarization-mode dispersion (PMD). For a given degree of PMD and pulse width there exists an optimum choice of group-velocity dispersion, for which solitons are most resistant to the effects of PMD. We also optimize the soliton power enhancement factor and find that solitons can propagate roughly twice the distance compared to linear pulses in the absence of group-velocity dispersion. Finally we investigate the PMD robustness of dispersion managed solitons, and in the case simulated we find no quantitative difference as compared to conventional solitons.
|
|
| 205. |
- Karlsson, Magnus, 1967, et al.
(författare)
-
Solitons: Soliton Communication Systems
- 2004
-
Ingår i: Encyclopedia of Modern Optics, Five-Volume Set. - 9780123693952 ; , s. 65-72
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
|
|
| 206. |
- Karlsson, Magnus, 1967, et al.
(författare)
-
Spectrally efficient four-dimensional modulation
- 2012
-
Ingår i: Optics InfoBase Conference Papers. - 2162-2701.
-
Konferensbidrag (refereegranskat)abstract
- We quantify the performance of regular four-dimensional constellations with high spectral efficiency, and compare the sensitivity gain relative to rectangular QAM. Gains up to 1.51 and 1.97 dB over the corresponding QAM formats can be achieved.
|
|
| 207. |
- Karlsson, Magnus, 1967, et al.
(författare)
-
Super-Gaussian approximation of the fundamental radial mode in nonlinear parabolic-index optical fibers
- 1992
-
Ingår i: Journal of the Optical Society of America B: Optical Physics. - 1520-8540 .- 0740-3224. ; 9:9, s. 1558-1562
-
Tidskriftsartikel (refereegranskat)abstract
- Using a direct variational technique involving super-Gaussian trial functions, we find approximate solutions for the fundamental radial mode of an optical wave propagating in a nonlinear parabolic-index fiber. A detailed examination is made of the amplitude, width, radial profile, and longitudinal phase shift of the stationary solutions that represent a two-dimensional balance among diffraction, nonlinear self-focusing, and linear wave guiding. For pulse powers below the self-focusing power, the stationary solutions are stabilized by the parabolic index variation.
|
|
| 208. |
|
|
| 209. |
|
|
| 210. |
- Karlsson, Magnus, 1967
(författare)
-
Transmission Systems With Low Noise Phase-Sensitive Parametric Amplifiers
- 2016
-
Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 34:5, s. 1411-1423
-
Tidskriftsartikel (refereegranskat)abstract
- This tutorial reviews the recent research on fiber-based phase-sensitive amplifiers (PSAs), and describes how they can be used in transmission systems. We describe the fundamentals of parametric amplifiers, their history, and their basic properties. Special emphasis is given to the noise properties and their implementation in transmission systems. The copier-PSA setup is described and compared to phase-insensitive links, and we describe the challenges in implementing these systems. Finally, we describe the polarization properties of vector PSAs, and the PSA use in compensation of nonlinear distortions.
|
|
