  In Letter [1], we reported our finding on the physical origin of wide
band-gap opening in planar nanostrips, as derived by application of periodic
width modulations in the magnetic waveguides. K. Di et al. in their Comment[2],
however, argued that the band gap can be reduced remarkably by applying a
linear combination of symmetric and antisymmetric fields (see 'A+B' in the
inset of Fig. 1(a)). They also insisted that they could find a complete set of
magnonic bands based on all of the mode symmetries. However, their work does
not constitute grounds for judging our method "wrong" and our conclusions
"erroneous". Moreover, the excitation field alluded to in the Comment is not
sufficiently general to obtain the complete set of magnonic band structures,
but rather remains specific. The grounds of these conclusions, drawn from our
further work, are the following.
