Showing papers on "Polarization mode dispersion published in 1978"
TL;DR: The resulting mode dispersion in short fiber lengths from the depolarization of broad-bandwidth light is measured, in good agreement with the observed birefringence.
Abstract: In real single-mode optical fibers, imperfections cause the two possible polarizations to propagate at different phase velocities This birefringence leads to different group velocities We have measured the resulting mode dispersion in short fiber lengths (05-25 m) from the depolarization of broad-bandwidth light In a typical fiber we found 30 psec/km at 069-microm wavelength, in good agreement with the observed birefringence The effect of mode dispersion can be compensated by a +/-68 degrees double twist midway along the fiber, interchanging the fast and slow modes
182 citations
TL;DR: In this paper, the modal dispersion in the optical fiber with truncated parabolic index distribution is analyzed theoretically in detail by using a variational method, taking the influence of the cladding upon the propagating modes into consideration.
Abstract: The use of a parabolic-index fiber as an optical transmission line has been receiving extensive attention because of its excellent mode dispersion characteristics. In the present paper, the modal dispersion in the optical fiber with truncated parabolic index distribution is analyzed theoretically in detail by using a variational method. Taking the influence of the cladding upon the propagating modes into consideration, it is found that there exists an optimum index distribution for which the modal dispersion is minimized. The standard deviation of the normalized group delay of propagating modes is used to estimate the modal dispersion behavior of the fiber.
26 citations
TL;DR: In this paper, a method based on the selective mode excitation at different wavelengths for studying the profile dispersion influence on the modal dispersion was described, which is able to determine either the optimum wavelength at which the fiber should be operated or the correction needed for optimising the index profile at a given wavelength.
Abstract: We describe a method based on the selective mode excitation at different wavelengths for studying the profile dispersion influence on the modal dispersion. By using this technique, we are able to determine either the optimum wavelength at which the fibre should be operated or the correction needed for optimising the index profile at a given wavelength.
11 citations
TL;DR: An efficient method is presented which helps to explain the interaction of both effects, shows a new way of minimizing the total dispersion by matching the two effects, and simplifies the calculation of pulse broadening in imperfect real fibers.
Abstract: Group delay differences among modes, which limit the bandwidth of optical fibers, arise not only from distortions of the refractive profile but also from profile dispersion caused by the dependence of the profile contour on wavelength. An efficient method is presented which helps to explain the interaction of both effects, shows a new way of minimizing the total dispersion by matching the two effects, and simplifies the calculation of pulse broadening in imperfect real fibers.
6 citations
TL;DR: In this article, the effect of strong mode coupling on modal dispersion in optical fibers has been investigated and the role of the initial pulse length and the source coherence time has been elucidated.
Abstract: The effect of strong mode coupling on modal dispersion in optical fibers has been investigated. The pulse dispersion turns out to be qualitatively different from the one relative to the weak-coupling case, while it exhibits a drastic reduction as compared with that of the uncoupled case. The role of the initial pulse length and of the source coherence time has been elucidated.
3 citations
TL;DR: Modal dispersion is explained through the frequency dependence of modal caustics in the ray optics treatment of propagation in multimode optical fibers.
Abstract: Modal dispersion is explained through the frequency dependence of modal caustics in the ray optics treatment of propagation in multimode optical fibers. Examples are shown for different index profiles that give rise to dispersion equalization or deterioration.
2 citations