Demonstration of a nanophotonic switching operation by optical near-field energy transfer

We have demonstrated the operation of a nanophotonic switch that uses three CuCl quantum cubes with a size ratio of 1:√:2. The switching mechanism is based on resonant optical near-field energy transfer between the resonant quantized excitonic energy levels of the quantum cubes. Using near-field optical spectroscopy, we observed a switching rise time of less than 100 ps and a repetition rate of 80 MHz. These results suggest the possibility of making a nanophotonic switching device smaller than 20 nm with a figure of merit 10–100 times higher than that of a conventional photonic switch.