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Arora, S. (author), Bauer, T.A. (author), Parappurath, N. (author), Barczyk, R.T. (author), Verhagen, E. (author), Kuipers, L. (author)We measure the local near-field spin in topological edge state waveguides that emulate the quantum spin Hall effect. We reveal a highly structured spin density distribution that is not linked to a unique pseudospin value. From experimental near-field real-space maps and numerical calculations, we confirm that this local structure is essential...journal article 2022
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Barczyk, R.T. (author), Parappurath, Nikhil (author), Arora, S. (author), Bauer, T.A. (author), Kuipers, L. (author), Verhagen, Ewold (author)The introduction of topological concepts to the design of photonic crystal cavities holds great promise for applications in integrated photonics due to the prospect of topological protection. This study examines the signatures of topological light confinement in the leakage radiation of 2D topological photonic crystal cavities. The cavities are...journal article 2022
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Arora, S. (author), Bauer, T.A. (author), Barczyk, René (author), Verhagen, Ewold (author), Kuipers, L. (author)Topological on-chip photonics based on tailored photonic crystals (PhCs) that emulate quantum valley-Hall effects has recently gained widespread interest owing to its promise of robust unidirectional transport of classical and quantum information. We present a direct quantitative evaluation of topological photonic edge eigenstates and their...journal article 2021
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Parappurath, Nikhil (author), Alpeggiani, F. (author), Kuipers, L. (author), Verhagen, Ewold (author)Topological protection in photonics offers new prospects for guiding and manipulating classical and quantum information. The mechanism of spin-orbit coupling promises the emergence of edge states that are helical, exhibiting unidirectional propagation that is topologically protected against back scattering. We directly observe the topological...journal article 2020
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Parappurath, N. (author), Alpeggiani, F. (author), Kuipers, L. (author), Verhagen, Ewold (author)We observe that the asymmetric transmission (AT) through photonic systems with a resonant chiral response is strongly related to the far-field properties of eigenmodes of the system. This understanding can be used to predict the AT for any resonant system from its complex eigenmodes. We find that the resonant chiral phenomenon of AT is...journal article 2017
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Alpeggiani, F. (author), Parappurath, N. (author), Verhagen, E. (author), Kuipers, L. (author)It is well known that the quasinormal modes (or resonant states) of photonic structures can be associated with the poles of the scattering matrix of the system in the complex-frequency plane. In this work, the inverse problem, i.e., the reconstruction of the scattering matrix from the knowledge of the quasinormal modes, is addressed. We develop...journal article 2017