Design of three-input nanophotonic AND gates

摘要

By modifying the design of an existing two-input nanophotonic AND gate, whose operation is based on optical near-field (ONF) interactions among three neighboring quantum dots (QDs), we have improved the gate ON/OFF ratio by up to about 9 dB. To do this, we have eliminated the possibility of direct ONF interaction between the input and output dots. Then, by adding another QD, as the second control dot to both existing and the modified two-input architectures, we have proposed two new three-input nanophotonic AND gate schemes-one with direct ONF interaction between its input and output dots, and the other without such interaction. Although, the former gate turns on relatively faster, one of its three possible ON/OFF ratios are shown to be about 7.3 dB lower than the latter. The differences in two other possible ON/OFF ratios of the two new gates are insignificant.