  We demonstrate the emergence of transparent behavior in a chain of
periodically spaced non-identical quantums emitters coupled to a waveguide, in
the special case when the inter-atomic separation is a half-integral multiple
of the resonant wavelength, i.e. $kL$ is an integral multiple of $\pi$, with
$k$ being the spatial frequency and $L$ the spatial periodicity. When equal but
opposite frequency detunings are assigned in pairs to a system of even number
of atoms, perfect transmission ensues. When the chain size is odd, a similar
assignment leads to the disappearance of collective effects as the odd atom
determines the spectral behavior. We also manifest the robustness of these
features against dissipative effects and show, how the spectral behavior hinges
significantly on the relative detunings between the atoms as compared to the
decay rate. A key distinction from the phenomenon of Electromagnetically
Induced Transparency (EIT) is that in the waveguide case, the presence of an
intrinsic waveguide mediated phase coupling between the atoms strongly affects
the transport properties. Furthermore, while reciprocity in single-photon
transport does not generally hold due to the phase coupling, we observe an
interesting exception for $kL = n\pi$ at which the waveguide demonstrates
reciprocal behavior with regard to both the transmission and reflection
coefficients.
