Principal States of Polarization for an Optical Pulse

We propose a generalized definition of principal states of polarization for an optical pusle with arbitrary spectral components. Similar to the principal states defined by Poole et at., we show that regardless of the spectral components of the pulse, there exist two orthogonal input states which minimize/maximize the delay of the pulse. At the output of the system, the principal states of the pulse, although depolarized, are also always orthogonal to each other.