title: Integrating Sphere Microscopy for Direct Absorption Measurements of Single Nanostructures.
abstract: Nanoscale materials are promising for optoelectronic devices because their physical dimensions are on the order of the wavelength of light. This leads to a variety of complex optical phenomena that, for instance, enhance absorption and emission. However, quantifying the performance of these nanoscale devices frequently requires measuring absolute absorption at the nanoscale, and remarkably, there is no general method capable of doing so directly. Here, we present such a method based on an integrating sphere but modified to achieve submicron spatial resolution. We explore the limits of this technique by using it to measure spatial and spectral absorptance profiles on a wide variety of nanoscale systems, including different combinations of weakly and strongly absorbing and scattering nanomaterials (Si and GaAs nanowires, Au nanoparticles). This measurement technique provides quantitative information about local optical properties that are crucial for improving any optoelectronic device with nanoscale dimensions or nanoscale surface texturing.
authors.affiliation: Center for Nanophotonics, AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands.
authors.forename: Sander A
authors.identifier: 0000-0002-7742-0615
authors.initials: SA
authors.lastname: Mann
authors.affiliation: Center for Nanophotonics, AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands.
authors.forename: Beniamino
authors.initials: B
authors.lastname: Sciacca
authors.affiliation: Department of Electronic and Electrical Engineering, University College London , London WC1E 7JE, United Kingdom.
authors.forename: Yunyan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Center for Nanophotonics, AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands.
authors.forename: Jia
authors.initials: J
authors.lastname: Wang
authors.affiliation: Center for Nanophotonics, AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands.
authors.forename: Evgenia
authors.initials: E
authors.lastname: Kontoleta
authors.affiliation: Department of Electronic and Electrical Engineering, University College London , London WC1E 7JE, United Kingdom.
authors.forename: Huiyun
authors.initials: H
authors.lastname: Liu
authors.affiliation: Center for Nanophotonics, AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands.
authors.forename: Erik C
authors.identifier: 0000-0002-9158-8326
authors.initials: EC
authors.lastname: Garnett
keywords: Mie resonances; absorption spectroscopy; nanoparticles; nanowires; plasmon resonance; quantitative spectroscopy