  We propose and experimentally demonstrate non-destructive and noiseless
removal (filtering) of vacuum states from an arbitrary set of coherent states
of continuous variable systems. Errors i.e. vacuum states in the quantum
information are diagnosed through a weak measurement, and on that basis,
probabilistically filtered out. We consider three different filters based on
on/off detection phase stabilized and phase randomized homodyne detection. We
find that on/off etection, optimal in the ideal theoretical setting, is
superior to the homodyne strategy in a practical setting.
