Polarization mode dispersion in single-mode fibers

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 (0.5-2.5 m) from the depolarization of broad-bandwidth light. In a typical fiber we found 30 psec/km at 0.69-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.

PMD fundamentals: Polarization mode dispersion in optical fibers

“…n the more than 15 years since the introduction of the early concepts (1,2), the fundamentals of polarization mode dispersion (PMD) in optical fibers have become an important body of knowledge basic for the design of high-capacity optical communication systems. PMD effects are linear electromagnetic propagation phenomena occurring in so-called ''single-mode'' fibers.…”

Periodic compensation of polarization mode dispersion

“…Note also that averaging in Eqs. (6) and (7) corresponds to either collecting statistics over many realizations (many fibers or separated-intime states of birefringence of the same fiber) or spatial z averaging over one particular realization. In the latter case the correlation scale of the birefringent disorder is assumed to be much shorter than the averaging scale.…”

“…In the latter case the correlation scale of the birefringent disorder is assumed to be much shorter than the averaging scale. Following standard notations, 31 the path-integral formulation for the averaging is introduced into expression (6) for the convenience of notation and further manipulations and derivations. (See, e.g., Ref.…”

“…For this purpose we use Eq. (41) and average over VB statistics described by expression (6). The path-integral representation for the joint probability distribution function of ⍀ 1 ,...,⍀ n , ...,⍀ N , where the index n ϭ 1,...,N marks the set of frequencies, is…”

“…One prominent effect is polarization mode dispersion (PMD), which has been studied in the linear case in a seminal series of papers by Poole and co-authors, [1][2][3][4] and, to the present day, PMD has remained one of the major limitations of a transmission system. 5 The effects of PMD on pulse propagation have been studied experimentally, 6,7 and measurement techniques have been analyzed. 8,9 Inspired by experimental observations, 10 Poole and Wagner introduced the concept of principal states, 11 which has been used widely in theory 12,13 and experiments.…”