Projects per year

### Abstract

In this thesis we have performed quantum electrodynamics (QED) experiments
in photonic crystal (PhC) waveguides and cavity QED in the Anderson localized
regime in disordered PhC waveguides. Decay rate measurements of quantum
dots embedded in PhC waveguides has been used to map out the variations
in the local density of states (LDOS) in PhC waveguides. From decay rate
measurements on quantum dot lines temperature tuned in the vicinity of the
waveguide band edge, a β-factor for a single quantum dot of more then 85%
has been extracted. Finite difference time domain simulations (FDTD) for disordered
PhC waveguides have been used to conrm the existence of a densely
packed spectrum of strongly conned Anderson localized modes near the waveguide
band edge. An one-dimensional disordered model is used to model the
statistical properties of Anderson localized modes. As the localization lengths
decrease, a simultaneous increase in the average Q-factor and decrease in mode
volume is observed, which leads to a large probability of observing strong coupling
in disorder PhC waveguides. The effect of losses is shown to reduce the
largest Q-factors in the distribution and drastically lower the strong coupling
probability. The Q-factor distributions of Anderson localized modes have been
measured in PhC waveguides with articial induced disorder with embedded
emitters. The largest Q-factors are found in the sample with the smallest
amount of disorder. From a comparison with the waveguide model the localization
length is shown to increase from 3 − 7 um for no intentional disorder
to 25 um for 6% disorder. A distribution of losses is seen to be necessary to
explain the measured Q-factor distributions. Finally we have performed a cavity
QED experiment between single quantum dots and an Anderson localized
mode, where a β-factor of 94% has been measured.

Original language | English |
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Place of Publication | Kgs. Lyngby, Denmark |
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Publisher | Technical University of Denmark |

Number of pages | 110 |

ISBN (Print) | 87-92062-64-4 |

Publication status | Published - 2011 |

## Projects

- 1 Finished

## Fotonisk Krystal en-fotonkileder

Nielsen, H. T., Lodahl, P., Mortensen, N. A., Andersen, U. L. & Vos, W. L.

Technical University of Denmark

15/04/2008 → 24/08/2011

Project: PhD

## Cite this

Nielsen, H. T. (2011).

*Quantum Electrodynamics in Photonic Crystal Waveguides*. Technical University of Denmark.