Second order polarization mode dispersion (SOPMD) is a coupling mechanism between polarization and frequency. Take our photon to be the following tensor product:
$\psi = \int \gamma_{\omega} | \omega \rangle \otimes (\alpha |H \rangle + \beta | V \rangle )d \omega$
then, can we model SOPMD as an entangling operator, $O_{SO}$, on this joint space? Furthermore, can we model certain kinds of noise in fibre transmission systems as this operator, $O_{SO}$, followed by the tracing out of one or both of polarization or frequency?
$\rho^{\prime} = Tr_{Pol} (O_{SO} \rho O_{SO}^{\dagger})$