Goos–Hänchen Shift Spatially Resolves Magneto-Optical Kerr Effect Enhancement in Magnetoplasmonic Crystals

Abstract

We report on how observation of the Goos−Hanchen (GH) shift can be used to spatially resolve the transverse magneto-optical Kerr effect (TMOKE) enhancement in all-nickel magnetoplasmonic crystals (MPCs). First, the excitation of surface plasmons in the MPCs leads to a 15.3 μm (18λ) GH shift. Then, in the presence of a transverse magnetic field, the modulation of the lateral spatial intensity distribution of the reflected light [TMOKE(x)], caused by the GH shift, reaches 4.7% in the experiment. The spatially resolved TMOKE(x) values are several times higher compared to those from conventional TMOKE measurements in the MPCs. The concept of the spatially resolved magneto-optical effects under GH shift can be further extended to other magnetophotonic nanodevices for additional enhancing magneto-optical effects, sensing, and light modulation applications.

Broadband Enhancement of Magneto-Optical Effects in Hybrid Waveguide-Plasmonic Surfaces for Sensing

“…Magneto-optical (MO) phenomena have been exploited in dynamically tunable optical devices, including active magneto-chiral nanophotonic sensors and switches, − magnetoplasmonic waveguides and routers, − magneto-optical modulators, − and magnetoplasmonic biosensors. , Of particular interest is the potential for spatially resolved measurements and ultrafast all-optical modulation of MO response, which may redefine the boundaries of magnetoplasmonic biosensing. This type of sensing is based on the sharp Fano-like curves associated with the transverse MO Kerr effect (TMOKE), whose resolution is superior to the broad plasmonic resonances. , TMOKE is characterized by the modulation of reflectivity amplitude ( R p ( m = ±1)) upon inversion of magnetization direction ( m = ± 1) along the magnetized axis.…”