two quick beginner questions

First off, excellent work on this program.

I am relatively new to the theory behind photonic crystals, and being
an experimentalist, my theory abilities aren't what they should be.

I am using using MPB primarily to look at the band structures of 1D
periodic PhCs, primarily looking for the band gaps. My questions are,
MPB gives the y-axis of a band diagram (frequency) in units of (c/a);
how do I get those values into the traditionally reported "normalized
units" of frequency*(a/(2 pi c)) as one usually sees in the
literature? Secondly, how do I extract a wavelength from these values,
for instance if I were constructing a dielectric mirror, how would I
figure out the band of reflected wavelengths?

I realize these are relatively simple questions with, most likely,
equally simple answers; but any help you can provide would be
appreciated.

Thanks,
Scott.