Projects per year
Abstract
This thesis concerns the propagation of optical pulses in semiconductor waveguide structures with particular focus on methods for achieving slow light or signal delays.
Experimental pulse propagation measurements of pulses with a duration of 180 fs, transmitted through quantum well based waveguide structures, are presented. Simultaneous measurements of the pulse transmission and delay are
measured as a function of input pulse energy for various applied electrical potentials.
Electrically controlled pulse delay and advancement are demonstrated and compared with a theoretical model. The limits of the model as well as the underlying physical mechanisms are analysed and discussed.
A method to achieve slow light by electromagnetically induced transparency (EIT) in an inhomogeneously broadened quantum dot medium is proposed.
The basic principles of EIT are assessed and the main dissimilarities between an atomic and a quantum dot medium are discussed. Three generic schemes are compared, showing that only one of the schemes are viable for slow light
in an inhomogeneously broadened medium. The principal differences between the schemes are analysed and discussed. Propagation calculations of the three
schemes are presented and compared together with estimates of the achievable delay and transmission.
Finally, measurements of the ultra fast gain dynamics of a quantum dot semiconductor optical amplifier are presented. The experiment is based on degenerate pump-probe transmission spectroscopy using 180 fs pulses. Both
the wavelength dependence as well as the applied current density dependence are investigated. Two characteristic relaxation rates of 0.2 ps and 1 ps are
extracted based on a theoretical model. The choice of model and the underlying physical processes of the measurements are discussed.
Original language | English |
---|
Place of Publication | Kgs. Lyngby, Denmark |
---|---|
Publisher | Technical University of Denmark |
Number of pages | 152 |
ISBN (Print) | 87-92062-36-9 |
Publication status | Published - May 2010 |
Fingerprint
Dive into the research topics of 'Slow light and pulse propagation in semiconductor waveguides'. Together they form a unique fingerprint.Projects
- 1 Finished
-
Processing and Characterization of Quantum dot Devices
Hansen, P. L. (PhD Student), Mork, J. (Main Supervisor), Poel, M. V. D. (Supervisor), Yvind, K. (Supervisor), Hvam, J. M. (Examiner), Eisenstein, G. (Examiner) & Marcinkevicius, S. (Examiner)
15/06/2006 → 26/05/2010
Project: PhD