title: Spatial resolution effect of light coupling structures.
abstract: The coupling of light between free space and thin film semiconductors is an essential requirement of modern optoelectronic technology. For monochromatic and single mode devices, high performance grating couplers have been developed that are well understood. For broadband and multimode devices, however, more complex structures, here referred to as "coupling surfaces", are required, which are often difficult to realise technologically. We identify general design rules based on the Fourier properties of the coupling surface and show how they can be used to determine the spatial resolution required for the coupler's fabrication. To our knowledge, this question has not been previously addressed, but it is important for the understanding of diffractive nanostructures and their technological realisation. We exemplify our insights with solar cells and UV photodetectors, where high-performance nanostructures that can be realised cost-effectively are essential.
authors.affiliation: State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun-Yat Sen University, Guangzhou, 510275, China.
authors.forename: Juntao
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun-Yat Sen University, Guangzhou, 510275, China.|Department of Physics, University of York, York, YO10 5DD, UK.
authors.forename: Kezheng
authors.initials: K
authors.lastname: Li
authors.affiliation: Department of Physics, University of York, York, YO10 5DD, UK.
authors.forename: Christian
authors.initials: C
authors.lastname: Schuster
authors.affiliation: State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun-Yat Sen University, Guangzhou, 510275, China.
authors.forename: Rongbin
authors.initials: R
authors.lastname: Su
authors.affiliation: State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun-Yat Sen University, Guangzhou, 510275, China.
authors.forename: Xuehua
authors.initials: X
authors.lastname: Wang
authors.affiliation: Electrical Engineering Department, University of São Paulo,Av. Trabalhador Sãocarlense, 400, São Carlos-SP, Brazil.
authors.forename: Ben-Hur V
authors.initials: BH
authors.lastname: Borges
authors.affiliation: State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun-Yat Sen University, Guangzhou, 510275, China.|Department of Physics, University of York, York, YO10 5DD, UK.
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Krauss
authors.affiliation: Electrical Engineering Department, University of São Paulo,Av. Trabalhador Sãocarlense, 400, São Carlos-SP, Brazil.
authors.forename: Emiliano R
authors.initials: ER
authors.lastname: Martins