Ultrafast rerouting of light via slow modes in a nanophotonic directional coupler
We demonstrate that two coupled photonic-crystal waveguides can route two subsequently arriving light pulses to different output ports even though the pulses are only 3 ps apart. This rerouting of light is due to an ultrafast shift in the transmittance spectrum triggered by the generation of electrons and holes in the Si base material by a femtosecond laser pulse. The use of slow-light modes allows for a coupler length of only 5.2 μm. Since these modes are not directly involved, the 3 ps dead time is solely determined by the duration of the input pulse rather than its transit time through the device.
|Journal||Appl. Phys. Lett.|
Kampfrath, T, Beggs, D. M, White, T. P, Burresi, M, van Oosten, D, Krauss, T. F, & Kuipers, L. (2009). Ultrafast rerouting of light via slow modes in a nanophotonic directional coupler. Appl. Phys. Lett., 94(Article number: 241119), 1–3. doi:10.1063/1.3153989