Efficient all-optical dual-channel switches, logic gates, half-adder, and half-subtracter in a one-dimensional photonic heterostructure

We have proposed a kind of one-dimensional photonic heterostructure for efficient all-optical dual-channel switches, logic gates, half-adder, and half-subtracter, based on the combined usage of two high-quality and one low-quality resonant modes with their electric fields strongly enhanced in the same defect regions. By exciting the low-quality modes with a low-intensity pump beam, one can efficiently shift the spectral positions of two high-quality modes and thus simultaneously control the propagation of signals at two frequency channels. For an AlGaAs/SiO2 heterostructure with two GaAs defect regions, the peak pump intensity can be lower than 6.2mW/mm2. When the frequency of the signal light is properly set relative to the two high-quality modes, its propagation can be logically controlled by pump beams with low intensity on the order of 10mW/mm2. Moreover, the frequency interval between the two high-quality modes and that between the high- and low-quality modes are adjustable in a wide range.