Abstract

Because of the presence of linear birefringence, single-mode fibers are really bimodal. It has been shown¹ that in the case of constant birefringence, walk-off can be avoided by modulation; the two fractional pulses shift each other's central frequency such that any initial difference in group velocity is eliminated. As a result, they are self-trapped in the time domain. In real fibers, the orientation of the birefringence tends to shift randomly, scattering light from one polarization to another in the process. A simple model² has been used to study the effect of this random variation on solitons. The fast and slow axes are assumed to flip randomly at given intervals. It is found that for sufficiently small fiber polarization-dispersion parameters, splitting and excessive pulse broadening can be avoided. In this paper, the effect of random variation of birefringence is studied in more detail. Besides allowing for different orientations and a range of magnitudes of the birefringence, a finite autocorrelation length is also considered.

© 1990 Optical Society of America