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HL: Halbleiterphysik
HL 12: Poster I
HL 12.28: Poster
Montag, 8. März 2004, 16:30–19:00, Poster A
Tuning a 2-D silicon photonic crystal using nonlinear optics — •Stefan L. Schweizer1, Hong W. Tan2, Henry M. van Driel2, Ralf B. Wehrspohn1, and Ulrich Gösele3 — 1Universität Paderborn, Dept. Physik, 33095 Paderborn — 2Department of Physics, University of Toronto, Canada — 3MPI für Mikrostrukturphysik, Weinberg 2, 06120 Halle
Photonic crystals (PC) have unusual dispersion properties that can be used to control the propagation characteristics of light beams. However, for some potential active devices, one desires methods to tune these optical properties quickly. We use pump-probe reflectivity experiments with 130 fs pulses to demonstrate how the real (Kerr) and imaginary (two photon absorption) parts of a third order optical nonlinearity can tune the long (1.6 µm) and short wavelength (1.3 µm) band-edges of a stop gap in a 2-D silicon photonic crystal. A 2 µm pump pulse induces optical tuning of the 1.3 µm edge via the Kerr effect whereas a 1.76 µm pump pulse induces tuning of the 1.6 µm band edge via both Kerr and Drude effects with the latter related to 2-photon induced generation of free carriers with a lifetime of ≈900ps.