Faithin Omaha eBook Collection

Download or read book Optimized Down-conversion Source and State-characterization Tools for Quantum Optics written by Georg Harder and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Parametric down-conversion (PDC) has become a common source for quantum states of light. Nevertheless, despite a wide adoption in proof of principle experiments,practical applications in large networks for communication or simulation remain unfeasible due to the high demands on the performance of sources and processes. In this thesis, we continue to develop PDC sources with the goal of increasing the quality and size of nonclassical states. We realize a source which produces photon pairs with high indistinguishability into a single spatial and spectral mode, simplifying potential integration into a multisource quantum network. We further demonstrate that the single-mode operation is maintained in the multiphoton regime by measuring photon-number correlations between the two down-conversion ports with up to 80 photons in each port. This demonstrates that the few-photon regime of current experiments based on PDC can in principle be extended into a many-photon regime, greatly increasing the dimensionality of accessible Hilbert spaces and the size of nonclassical states. Complementing our work on sources, we investigate how quantum characterization schemes can be improved or simplified. We demonstrate that photon-number distributions can be inferred using only a single avalanche photodiode and a thermal noise source. We further investigate a technique called pattern tomography to analyze measurements with imperfect time-multiplexing detectors. This allows us to circumvent the challenging task of full detector tomography and reconstruct low-photon-number PDC states, heralded states and displaced states. Moreover, we develop and demonstrate a technique to infer vacuum two-mode squeezing with a phase-randomized local oscillator. This poses an alternative to homodyne detection, which requires phase stability. Finally, we show that nonclassical correlations can be certified... ; eng