Active photonic platforms for the mid-infrared to the THz regime using spintronic structures

Abstract

<jats:title>Abstract</jats:title><jats:p>Spintronics and Photonics constitute separately two disciplines of huge scientific and technological impact. Exploring their conceptual and practical overlap offers vast possibilities of research and a clear scope for the corresponding communities to merge and consider innovative ideas taking advantage of each other’s potentials. As an example, here we review the magnetic field modification of the optical response of photonic systems fabricated out of spintronic materials, or in which spintronic components are incorporated. This magnetic actuation is due to the Magneto Refractive Effect (MRE), which accounts for the change in the optical constants of a spintronic system due to the magnetic field induced modification of the electrical resistivity. Due to the direct implication of conduction electrons in this phenomenon, this change in the optical constants covers from the mid-infrared to the THz regime. After introducing the non-expert reader into the spintronic concepts relevant to this work, we then present the MRE exhibited by a variety of spintronic systems, and finally show the different applications of this property in the generation of active spintronic-photonic platforms.</jats:p>

A novel vibrational spectroscopy using spintronic–plasmonic antennas: Magneto-refractive surface-enhanced infrared absorption

“…[21][22][23] These spintronic-plasmonic metasurfaces have the peculiarity that their resonances can be modulated by applying a magnetic field. This is a consequence of the Magneto-Refractive Effect (MRE), 24,25 which accounts for the change in the optical constants of the GMR multilayer due to the modification of the electrical resistivity induced by the magnetic field [Fig. 1(a)].…”

Magnetic modulation of mid and far-infrared plasmon resonances using the orientational magneto optical effect

“…17 By using giant magneto resistance (GMR) metallic multilayers, magnetic modulation in the mid and far-IR spectral ranges of plasmonic resonances in extraordinary optical transmission membranes, metallic rods, or in slits engraved in metallic layers have been already demonstrated. 18 The key element in all these structures is the metallic multilayer, which is composed of alternating layers of ferromagnetic and nonferromagnetic metals. The GMR effect is linked to the relative magnetic orientation between the magnetic layers, which strongly depends on the thickness of the non-magnetic spacer layer.…”

“…The magnetic modulation mechanism discussed here (OME) belongs to the same family than the MRE, being both effects linked to the spin dependent transport properties of ferromagnetic structures. 18 In GMR multilayers, the relaxation time of the majority and minority spin electrons depends on the relative orientation of the magnetizations of the adjacent ferromagnetic layers, which can be controlled by a magnetic field. This dependence of the relaxation times results in a change in the optical properties (MRE effect), and the magnetic modulation of the plasmon properties is achieved by changing the intensity of the magnetic field.…”