  Optical quantum routers which play a crucial role in quantum networks, have
been extensively studied in both theory and experiment, resulting in
significant advancements in their performance. However, these routers impose
stringent requirements for achieving optimal routing performance, where the
incident photon frequency must be in strict resonance with one or several
specific frequencies. To address this challenge, we have designed an efficient
quantum router capable of stable output with 100\% transfer rate over the
entire energy band of coupled-resonator waveguide (CRW) by coupling a giant
atom to two or more semi-infinite CRWs. We also explain and prove the
fundamental physical mechanism behind this distinctive phenomenon as the result
of destructive interference between two waves composing the final reflected
wave. We hope that quantum router with output results unaffected by the energy
of the incoming information carriers present a more reliable solution for the
implementation of quantum networks.
