--- res: bibo_abstract: - We realize and investigate a nonlinear metasurface taking advantage of intersubband transitions in ultranarrow GaN/AlN multi-quantum well heterostructures. Owing to huge band offsets, the structures offer resonant transitions in the telecom window around 1.55 µm. These heterostructures are functionalized with an array of plasmonic antennas featuring cross-polarized resonances at these near-infrared wavelengths and their second harmonic. This kind of nonlinear metasurface allows for substantial second-harmonic generation at normal incidence which is completely absent for an antenna array without the multi-quantum well structure underneath. While the second harmonic is originally radiated only into the plane of the quantum wells, a proper geometrical arrangement of the plasmonic elements permits the redirection of the second-harmonic light to free-space radiation, which is emitted perpendicular to the surface.@eng bibo_authorlist: - foaf_Person: foaf_givenName: Jan foaf_name: Mundry, Jan foaf_surname: Mundry - foaf_Person: foaf_givenName: Florian foaf_name: Spreyer, Florian foaf_surname: Spreyer - foaf_Person: foaf_givenName: Valentin foaf_name: Jmerik, Valentin foaf_surname: Jmerik - foaf_Person: foaf_givenName: Sergey foaf_name: Ivanov, Sergey foaf_surname: Ivanov - foaf_Person: foaf_givenName: Thomas foaf_name: Zentgraf, Thomas foaf_surname: Zentgraf foaf_workInfoHomepage: http://www.librecat.org/personId=30525 orcid: 0000-0002-8662-1101 - foaf_Person: foaf_givenName: Markus foaf_name: Betz, Markus foaf_surname: Betz bibo_doi: 10.1364/ome.426236 bibo_issue: '7' bibo_volume: 11 dct_date: 2021^xs_gYear dct_isPartOf: - http://id.crossref.org/issn/2159-3930 dct_language: eng dct_publisher: OSA@ dct_title: Nonlinear metasurface combining telecom-range intersubband transitions in GaN/AlN quantum wells with resonant plasmonic antenna arrays@ ...