Design of single-dual channel conversion filter based on one-dimensional photonic crystal

This study proposes a quantum well photonic crystal to realize a single-dual channel conversion filter in the optical communication band, which aggregates dual-channel into single-channel by reducing the coupling strength between the air defect modes. When the photonic crystal structure with defect mode is symmetric, there is a single channel in the forbidden bandgap due to the disappearance of coupling between the two channels and the transmittance is up to 100%. The coupling coefficient a is inversely proportional to the period number M. When M is greater than the threshold-2N, the transmittance of the channel gradually decreases as M increases, correspondingly. The proposed filter can be applied in wavelength division multiplexing to increase the network capacity.