Context of this work
The IQO group is working within a research project (funded by the Deutsche Forschungsgemeinschaft DFG) on the development of integrated optical, efficient true single photon source in the telecom regime. A time multiplexing scheme will be used to provide photons “on demand” with a high probability of triggered single photon generation and strongly suppressed multi-photon contributions.
The ultimate goal is to develop a time multiplexed source which is based on integrated optical circuits realized in LiNbO3. A first circuit is used for photon pair generation via parametric down-conversion (PDC) in a periodically poled section of the substrate. A monolithically integrated subsequent directional coupler acts as a wavelength division multiplexer to spatially separate the generated signal and idler photons. The device will be pumped by a burst of pump pulses. The signal photons are used to herald the presence of pair generation processes. With a fiber-based time-multiplexing detector a herald detection with photon-number resolution will be implemented. The idler photons are routed to a second integrated circuit with two electro-optic 2x2 switches. The first idler photon within the burst - which is heralded by detecting the corresponding signal photon – is routed via the first electro-optic switch to a fiber loop. The stored photon is released from that loop at the end of the burst cycle.
Topics for master/bachelor theses:
The realization of this complex source requires the development of specific integrated optical components and circuits and their implementation. Several sub-tasks can be defined which are well suited for master or bachelor theses. In particular the following topics are feasible:
- Optimization of fiber-waveguide interfacing
- Electro-optically controllable switch circuits and fiber-loops
- Design and performance studies of multiplexed single photon sources
Details of the contents are still a subject of discussion. If you are interested, feel free to contact us.
Please get in touch with
Prof. Dr. Christine Silberhorn
Phone: 05251 60 5884
Dr. Harald Herrmann
Phone: 05251 60 5879