ORCID Profile
0000-0003-2330-1802
Current Organisations
University of California, San Diego
,
SWPS Uniwersytet Humanistycznospołeczny
,
Institute of Materials Research and Engineering
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Publisher: Springer Science and Business Media LLC
Date: 20-01-2022
DOI: 10.1038/S41377-021-00707-2
Abstract: Bound-states-in-the-continuum (BIC) is an emerging concept in nanophotonics with potential impact in applications, such as hyperspectral imaging, mirror-less lasing, and nonlinear harmonic generation. As true BIC modes are non-radiative, they cannot be excited by using propagating light to investigate their optical characteristics. In this paper, for the 1st time, we map out the strong near-field localization of the true BIC resonance on arrays of silicon nanoantennas, via electron energy loss spectroscopy with a sub-1-nm electron beam. By systematically breaking the designed antenna symmetry, emissive quasi-BIC resonances become visible. This gives a unique experimental tool to determine the coherent interaction length, which we show to require at least six neighboring antenna elements. More importantly, we demonstrate that quasi-BIC resonances are able to enhance localized light emission via the Purcell effect by at least 60 times, as compared to unpatterned silicon. This work is expected to enable practical applications of designed, ultra-compact BIC antennas such as for the controlled, localized excitation of quantum emitters.
Publisher: American Chemical Society (ACS)
Date: 10-11-2022
DOI: 10.1021/ACS.NANOLETT.2C03007
Abstract: Reconfigurable metamaterials require constituent nanostructures to demonstrate switching of shapes with external stimuli. Yet, a longstanding challenge is in overcoming stiction caused by van der Waals forces in the deformed configuration, which impedes shape recovery. Here, we introduce stiff shape memory polymers. This designer material has a storage modulus of ∼5.2 GPa at room temperature and ∼90 MPa in the rubbery state at 150 °C, 1 order of magnitude higher than those in previous reports. Nanopillars with diameters of ∼400 nm and an aspect ratio as high as ∼10 were printed by two-photon lithography. Experimentally, we observe shape recovery as collapsed and touching structures overcome stiction to stand back up. We develop a theoretical model to explain the recoverability of these sub-micrometer structures. Reconfigurable structural color prints with a resolution of 21150 dots per inch and holograms are demonstrated, indicating potential applications of the stiff shape memory polymers in high-resolution reconfigurable nanophotonics.
Publisher: Cambridge University Press (CUP)
Date: 2015
DOI: 10.1017/S0140525X14001058
Abstract: Pessoa (2013) makes an impressive case that emotion, motivation, and cognition are neurally intertwined. Our commentary broadens the discussion to the functional, “mind” level. We argue that philosophical and computational considerations justify some modern “separatist” views. We highlight several psychological phenomena that illustrate independence, including affective and motivational reactions to rudimentary inputs, and the guiding role of such reactions in cognition.
Publisher: American Chemical Society (ACS)
Date: 22-07-2022
DOI: 10.1021/ACS.NANOLETT.2C01349
Abstract: Resonant metasurfaces provide a unique platform for enhancing multiwave nonlinear interactions. However, the difficulties over mode matching and material transparency place significant challenges in the enhancement of these multiwave processes. Here we demonstrate efficient nonlinear sum-frequency generation (SFG) in multiresonant GaP metasurfaces based on guided-wave bound-state in the continuum resonances. The excitation of the metasurface by two near-infrared input beams generates strong SFG in the visible spectrum with a conversion efficiency of 2.5 × 10
Publisher: Psychology Press
Date: 04-05-2012
Publisher: American Chemical Society (ACS)
Date: 20-01-2023
Publisher: Psychology Press
Date: 31-05-2010
Publisher: Psychology Press
Date: 06-12-2012
Publisher: Frontiers Media SA
Date: 23-03-2017
Location: United States of America
Location: Korea, Republic of
No related grants have been discovered for Piotr Winkielman.