When a nonlinear oscillator is driven externally, it may become transparent
, i.e., the output response appears without any dispersion or distortion. S
uch counter-intuitive feature, in fact, is a unique zero-dispersion nonline
ar resonance (ZDNR). Herein, it is examined on the base of a generic input-
output analysis. The conditions for ZDNR have been clarified and a power la
w relation has been established to feature the interplay with noise.