Tunable bandpass routers of single photons with three-level emitters

Frequency selectivity of routing signals in quantum channels is of great significance for a quantum optical network. We have proposed a novel tunable bandpass router constructed by two waveguides linked mediately via a driven three-level emitter. The routing properties in the output port are investigated theoretically by using the real-space Hamiltonian. Numerical results show that the continuous central frequencies on demand of routing photons can be manipulated almost linearly by tuning the driving field, and high routing efficiencies of resonance transmission can be achieved via reflection feedback. The proposed routing system could be exploited potentially in designing other quantum optical devices and quantum information processing.