We derive an analytic expression for the evolution of the differential group delay (DGD) in a fiber-optic circulating loop. We distill a simple analytic solution for the <i>average</i> DGD and show that it accumulates approximately linearly with transmission distance. The scaling of this linear function is confirmed experimentally using a long-haul fiber-optic transmission test-bed. This result is contrasted with DGD accumulation in a long straight-line transmission system, where the average DGD accumulates as a square root of the system’s length.
© 2004 Optical Society of America
(060.2300) Fiber optics and optical communications : Fiber measurements
(060.2330) Fiber optics and optical communications : Fiber optics communications
(060.2360) Fiber optics and optical communications : Fiber optics links and subsystems
(060.5530) Fiber optics and optical communications : Pulse propagation and temporal solitons
T. I. Lakoba, C. Dorrer, and D. N. Maywar, "Polarization-mode dispersion of a circulating loop," J. Opt. Soc. Am. B 21, 243-248 (2004)