Measurement of ultralow PMD in optical fibers and components

We describe the principle of an instrument for PMD determination over nearly four orders of magnitude, from under 10 fs to 40 ps, through an adaptive combination of three standard PMD measurement methods: the interferometric, fixed analyzer, and Poincare sphere methods. The key elements in this adaptive instrument are a conventional interferometric PMD analyzer and a rotating polarizer. The fringe patterns, obtained with a few settings of the rotating polarizer, are used to perform either a direct time-domain analysis or a frequency-domain analysis after Fourier transform.