Regensburg 2010 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 52: Heterostructures

HL 52.2: Vortrag

Donnerstag, 25. März 2010, 10:15–10:30, H17

Bandpass Switching in an Optical Microcavity by a Picosecond Acoustics — Thorsten Berstermann¹, •Christian Brüggemann¹, Michael Bombeck¹, Andrey V. Akimov^2,3, Dimitri R. Yakovlev^1,3, Carsten Kruse⁴, Detlef Hommel⁴ und Manfred Bayer¹ — ¹Experimentelle Physik 2, Technische Universität Dortmund, D-44227 Dortmund, Germany — ²School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom — ³A. F. Ioffe Physical Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia — ⁴Institut für Festkörperphysik, Abteilung Halbleiterepitaxie, Universität Bremen, D-28359 Bremen, Germany

We present a new experimental approach for the energy modulation of the cavity mode of a semiconductor optical Bragg microcavity, that can be considered as an optical bandpass. This is accomplished by the application of picosecond strain pulses. The strain pulses are excited in a 100 nm Al thermoelastic transducer, evaporated on the opposite site of 100 µm GaAs substrate, by 100 fs (800 nm) laser pulses. They get injected into the substrate and travel towards the cavity. When the strain pulse hits the bragg structure, the layers and interfaces are shown to be significantly altered by the displacement of the interfaces and the photoelastic effect. The resulting energy modulation of the confined cavity mode is detected in reflection geometry, by white laser pulses, generated by the same source as the excitation beam on the Al transducer. This modulation is shown to be in the order of the spectral width of the cavity mode.