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Title: A parity-time symmetric coherent plasmonic absorber-amplifier

Non-Hermitian parity-time (PT)-symmetric optical potentials have led to a new class of unidirectional photonic components based on the spatially symmetric and balanced inclusion of loss and gain. While most proposed and implemented PT-symmetric optical devices have wavelength-scale dimensions, no physical constraints preclude development of subwavelength PT-symmetric components. We theoretically demonstrate a nanoscale PT-symmetric, all-optical plasmonic modulator capable of phase-controlled amplification and directional absorption. The modulator consists of two deeply subwavelength channels composed of either gain or loss dielectric material, embedded in a metallic cladding. When illuminating on-resonance by two counter-propagating plane waves, the aperture's total output can be modulated by changing the phase offset between the two waves. Modulation depths are greater than 10 dB, with output power varying from less than one half of the incident power to more than six times amplification. Off-resonance, the aperture possesses strong phase-controlled directionality with the output from one side varying from perfect absorption to strong scattering and transmission. The device design provides a platform for nanoscale all-optical modulators with gain while potentially enabling coherent perfect absorption and lasing in a single, compact structure.
Authors:
;  [1] ;  [2]
  1. Department of Materials Science and Engineering, Stanford University, Stanford, California 94305 (United States)
  2. Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States)
Publication Date:
OSTI Identifier:
22413081
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 6; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION; AMPLIFIERS; CLADDING; DIELECTRIC MATERIALS; GAIN; INCLUSIONS; METALS; MODULATION; NANOSTRUCTURES; P INVARIANCE; PLASMONS; SCATTERING; T INVARIANCE; WAVE PROPAGATION; WAVELENGTHS