PhD Defense by Tau Bernstorff Lehmann

In this thesis, the application of semiconductor quantum-dots in photonic crystals is explored as a resource for single-photon technology.  

Two platforms based on photonic crystals, a cavity and a waveguide, are examined as platforms single-photon sources. Both platforms demonstrate strong single-photon purity under quasi-resonant excitation. Furthermore the waveguide based platform demonstrates indistinguishable single-photons at timescales up to 13 ns. 

A setup for active demultiplexing of single-photons to a three-fold single-photon state is proposed. Using a fast electro-optical modulator, single-photons from a quantum-dot are routed on timescales of the exciton lifetime. Using active demultiplexing a three-fold single-photon state is generated at an extracted rate of 2.03±0.49 Hz. 

An on-chip power divider integrated with a quantum-dot is investigated. Correlation measurement of the photon statistic verifies the single-photon nature of the quantum-dot. Furthermore correlation measurement between the outputs of the power divider confirms the passive separation of the single-photon emission. 

A scheme for post-emission entanglement generation between single-photons from an efficient source is discussed. The possible applications of post-emission entanglement generation are presented. An experimental realization of the scheme are constructed and characterized using single-photons from an efficient source.