An article of footwear includes an upper and a sole assembly positioned beneath the upper. The video encoder also includes a motion estimator that determines a predicted motion vector for a given macroblock by reusing, as the predicted motion vector for the given macroblock, only the PMV computed by the entropy encoder for a macroblock immediately on top of the given macroblock. Thus, a random state of polarization of the pump signal, with respect to the various input signal wavelengths, improves the overall gain experienced by the system.