TY - BOOK

T1 - Single-photon manipulation in Nanophotonic Circuits

AU - Hansen, Sofie Lindskov

PY - 2017

Y1 - 2017

N2 - Quantum dots in photonic nanostructures has long been known to be a very powerfuland versatile solid-state platform for conducting quantum optics experiments.The present PhD thesis describes experimental demonstrations of single-photongeneration and subsequent manipulation all realized on a gallium arsenide platform.This platform offers near-unity coupling between embedded single-photonemitters and a photonic mode, as well as the ability to suppress decoherence mechanisms,making it highly suited for quantum information applications.In this thesis we show how a single-photon router can be realized on a chip withembedded quantum dots. This allows for on-chip generation and manipulation ofsingle photons. The router consists of an on-chip interferometer where the phasedifference between the arms of the interferometer is controlled electrically. Theresponse time of the device is experimentally shown to be in the sub-microsecondrange.The performance of the device is limited by the reflections from the out-couplinggratings used, and we thus developed a new type of out-coupler that reduces reflectionsas well as increases the coupling efficiency to the fiber. The grating design isinspired by a well-known design from silicon photonics and is adopted for quantumdot emission wavelengths. The new gratings offer a fivefold increase in efficiencycompared to the gratings used previously. These results are found from simulationsas well as transmission measurements and have recently been confirmed in singlephotonexperiments.Lastly, an examination of some of the possible applications of quantum dots efficientlycoupled to the propagating mode of a photonic crystal waveguide is presented.Specifically, we describe how we can realize propagation-direction-dependentlight-matter interactions in engineered nanostructures, and how we can utilize a wellcoupled quantum dot to realize giant nonlinearities at the single-photon level.

AB - Quantum dots in photonic nanostructures has long been known to be a very powerfuland versatile solid-state platform for conducting quantum optics experiments.The present PhD thesis describes experimental demonstrations of single-photongeneration and subsequent manipulation all realized on a gallium arsenide platform.This platform offers near-unity coupling between embedded single-photonemitters and a photonic mode, as well as the ability to suppress decoherence mechanisms,making it highly suited for quantum information applications.In this thesis we show how a single-photon router can be realized on a chip withembedded quantum dots. This allows for on-chip generation and manipulation ofsingle photons. The router consists of an on-chip interferometer where the phasedifference between the arms of the interferometer is controlled electrically. Theresponse time of the device is experimentally shown to be in the sub-microsecondrange.The performance of the device is limited by the reflections from the out-couplinggratings used, and we thus developed a new type of out-coupler that reduces reflectionsas well as increases the coupling efficiency to the fiber. The grating design isinspired by a well-known design from silicon photonics and is adopted for quantumdot emission wavelengths. The new gratings offer a fivefold increase in efficiencycompared to the gratings used previously. These results are found from simulationsas well as transmission measurements and have recently been confirmed in singlephotonexperiments.Lastly, an examination of some of the possible applications of quantum dots efficientlycoupled to the propagating mode of a photonic crystal waveguide is presented.Specifically, we describe how we can realize propagation-direction-dependentlight-matter interactions in engineered nanostructures, and how we can utilize a wellcoupled quantum dot to realize giant nonlinearities at the single-photon level.

UR - https://soeg.kb.dk/permalink/45KBDK_KGL/fbp0ps/alma99122711165105763

M3 - Ph.D. thesis

BT - Single-photon manipulation in Nanophotonic Circuits

PB - The Niels Bohr Institute, Faculty of Science, University of Copenhagen

ER -