Measurements of differential group delay and chromatic dispersion for LP01 and LP11 modes of few-mode fibers with depressed claddings

摘要

The chromatic dispersion of the LP11 mode in a few-mode fiber with low differential group delay is evaluated experimentally. A differential group delay of less than 100 ps/km around 1550 nm can be evaluated with the modal interferometer method. The white-light interferometric method confirms that the LP11 mode is behind the LP01 mode in the 1300-1600 nm wavelength region. The difference between the chromatic dispersion values of the two modes is less than 0.5 ps/kmm, which means that the optical pulse spreading characteristics of the LP11 mode are similar to those of the LP01 mode for fibers with depressed claddings.