Berlin 2008 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 24: Photonic crystals II

HL 24.8: Vortrag

Dienstag, 26. Februar 2008, 11:30–11:45, EW 202

Bistable lasing and ultrafast mode switching in photonic crystal microcavities — •Sergei V. Zhukovsky¹, Dmitry N. Chigrin¹, Andrei V. Lavrinenko², and Johann Kroha¹ — ¹Physikalisches Institut, Universität Bonn, Nussallee 12, 53115 Bonn, Germany — ²COM-DTU, Department of Communications, Optics, and Materials, NanoDTU, TU Denmark, Bld. 345V, 2800 Kgs.Lyngby, Denmark

We show analytically and numerically that a system based on coupled microcavities can exhibit bistable lasing. Bistability occurs when microcavity modes have similar intensity distributions within the gain region. Both incoherent (hole-burning) and coherent (population-pulsation) mode interaction processes contribute to the development of bistability. Unlike the modes of most ring-laser or polarization-bistable set-ups, the modes of coupled microcavities can still have different frequencies. The phase structure of the modes remains distinct, which makes them addressable for selective lasing using a pulsed injection signal with matching symmetry [1]. We demonstrate numerically that a switching of the laser wavelength by about 20 nm at the time scale of 10 ps is possible for twin coupled defects in a 2D photonic crystal lattice [1], by far exceeding the performance of a conventional (e.g., electrooptical or micromechanical) tuning of a microcavity. The results obtained can be used in the design of integrated optical components such as multiple-wavelength microlaser sources or optical memory cells (see [2]) with nearly monochromatic control signals.

[1] S. V. Zhukovsky et al, Phys. Rev. Lett. 99, 073902 (2007).

[2] M. Hill et al, Nature 432, 206 (2004).