title: Tuning of Magnetic Optical Response in a Dielectric Nanoparticle by Ultrafast Photoexcitation of Dense Electron-Hole Plasma.
abstract: We propose a novel approach for efficient tuning of optical properties of a high refractive index subwavelength nanoparticle with a magnetic Mie-type resonance by means of femtosecond laser irradiation. This concept is based on ultrafast photoinjection of dense (>10(20) cm(-3)) electron-hole plasma within such nanoparticle, drastically changing its transient dielectric permittivity. This allows manipulation by both electric and magnetic nanoparticle responses, resulting in dramatic changes of its scattering diagram and scattering cross section. We experimentally demonstrate 20% tuning of reflectance of a single silicon nanoparticle by femtosecond laser pulses with wavelength in the vicinity of the magnetic dipole resonance. Such a single-particle nanodevice enables designing of fast and ultracompact optical switchers and modulators.
authors.affiliation: ITMO University , St. Petersburg 197101, Russia.
authors.forename: Sergey
authors.initials: S
authors.lastname: Makarov
authors.affiliation: ITMO University , St. Petersburg 197101, Russia.|Lebedev Physical Institute , Moscow 119991, Russia.
authors.forename: Sergey
authors.initials: S
authors.lastname: Kudryashov
authors.affiliation: ITMO University , St. Petersburg 197101, Russia.|Laboratory of Renewable Energy Sources, St. Petersburg Academic University , St. Petersburg 195251, Russia.
authors.forename: Ivan
authors.initials: I
authors.lastname: Mukhin
authors.affiliation: Laboratory of Renewable Energy Sources, St. Petersburg Academic University , St. Petersburg 195251, Russia.
authors.forename: Alexey
authors.initials: A
authors.lastname: Mozharov
authors.affiliation: ITMO University , St. Petersburg 197101, Russia.
authors.forename: Valentin
authors.initials: V
authors.lastname: Milichko
authors.affiliation: ITMO University , St. Petersburg 197101, Russia.
authors.forename: Alexander
authors.initials: A
authors.lastname: Krasnok
authors.affiliation: ITMO University , St. Petersburg 197101, Russia.
authors.forename: Pavel
authors.initials: P
authors.lastname: Belov
keywords: Huygens source; dense electron−hole plasma; femtosecond laser; magnetic Mie-type resonance; silicon nanoparticles