To provide control of differential group delay in mode division multiplexed optical fiber systems.

It has been discovered that, within a group of optical fibers produced by methods designed to produce low Differential Group Delay (DGD), some optical fibers will show a positive DGD while others will show a negative DGD. That recognition allows optical fibers with excessive DGD to be combined in pairs, or other configurations, to produce transmission spans in which a positive (or negative) DGD partial span is compensated by a partial span of fibers with a negative (or positive) DGD. Pairs of optical fibers with positive and negative DGD coefficients respectively may be deliberately produced and assembled in a cable in a concatenated fashion to produce reduced overall DGD in long transmission spans.