  A scheme of quantum electrodynamic (QED) background-free radiative emission
of neutrino pair (RENP) is proposed in order to achieve precision determination
of neutrino properties so far not accessible. The important point for the
background rejection is the fact that the dispersion relation between wave
vector along propagating direction in wave guide (and in a photonic-crystal
type fiber) and frequency is modified by a discretized non-vanishing effective
mass. This effective mass acts as a cutoff of allowed frequencies, and one may
select the RENP photon energy region free of all macro-coherently amplified QED
processes by choosing the cutoff larger than the mass of neutrinos.
