  The distribution of ultra-narrow linewidth laser radiation is an integral
part of many challenging metrological applications. Changes in the optical
pathlength induced by environmental disturbances compromise the stability and
accuracy of optical fibre networks distributing the laser light and call for
active phase noise cancellation. Here we present a laboratory scale optical (at
578 nm) fibre network featuring all polarisation maintaining fibres in a setup
with low optical powers available and tracking voltage-controlled oscillators
implemented. The stability and accuracy of this system reach performance levels
below 1 * 10^(-19) after 10 000 s of averaging
