We demonstrate all-optical switching in quantum dots (QDs). The switching is studied in an integrated optical combiner circuit. This is a Mach–Zehnder interferometer with an unequal power distribution over the branches. The refractive index is intensity dependent in the branches due to the QDs. Large all-optical nonlinearities are measured. This device is aimed to avoid an unwanted 3-dB loss, fundamental in passive optical splitters.
Patent, E. A., Tol, van der, J. J. G. M., Binetti, P. R. A., Gong, Q., Oei, Y. S., Nötzel, R., ... Smit, M. K. (2004). First integrated combiner based on self-switching in quantum dots. IEEE Photonics Technology Letters, 16(10), 2308-2310. https://doi.org/10.1109/LPT.2004.833952