Magnetic-field modulation of surface plasmon polaritons on gratings

Abstract

The propagation of surface plasmon polaritons (SPPs) on gratings can be experimentally modified when magneto-optically active materials are used. We have observed this effect in Au-Co thin-film bilayers where a polymer grating was patterned on the upper surface. In addition, Au-Co-Au trilayers were grown on polycarbonate gratings, and the Co layer thicknesses and placement from the upper interface were varied to further investigate this effect. We show that the Co layer must be tailored to balance optical absorption and magneto-optical activity, while the pitch of the grating can be adjusted to tune the angular dependence of the field-dependent SPP excitation.

Magnetoplasmonics: Combining Magnetic and Plasmonic Functionalities

“…The optimization of each component is obtained with different thicknesses, and a compromise has to be established depending on which magnitude, R , ΔR pp or ΔR pp / R , we are interested in maximizing. Following this approach, Newman et al [ 140 ] and Grunnin et al [ 141 ] have studied the effect of such excitation in Ni and Co gratings as well as Ni gratings covered by Ag thin fi lms, and Clavero et al [ 142 ] analyze Au/Co/Au gratings, fi nding an enhancement of the MO activity correlated with the increase of the EM fi eld associated to the presence of SPPs in the system. Following this approach, Newman et al [ 140 ] and Grunnin et al [ 141 ] have studied the effect of such excitation in Ni and Co gratings as well as Ni gratings covered by Ag thin fi lms, and Clavero et al [ 142 ] analyze Au/Co/Au gratings, fi nding an enhancement of the MO activity correlated with the increase of the EM fi eld associated to the presence of SPPs in the system.…”

“…[ 78 ] In the preceding paragraphs, we have presented works in which Kretschmann geometry is used to excite SPPs, but this can also be achieved by the use of periodic systems such as gratings. Following this approach, Newman et al [ 140 ] and Grunnin et al [ 141 ] have studied the effect of such excitation in Ni and Co gratings as well as Ni gratings covered by Ag thin fi lms, and Clavero et al [ 142 ] analyze Au/Co/Au gratings, fi nding an enhancement of the MO activity correlated with the increase of the EM fi eld associated to the presence of SPPs in the system.…”

Magneto-optical Kerr effect enhancement at the Wood's anomaly in magnetoplasmonic crystals

“…In such structures significant Faraday angles and magneto-optical Kerr effect (MOKE) values were achieved [2][3][4][5][6][7][8]. Another approach deals with enhancement of magneto-optical response of periodically structured magnetic metallic materials, where propagating surface plasmon-polaritons (SPPs) can be excited due to the phase-matching between wavevectors of incident light and SPP and the vector of reciprocal lattice [9][10][11][12]. By analogy with magnetophotonic crystals, such materials can be called as magnetoplasmonic crystals controlling SPP generation and propagation by periodicity parameters.…”

Plasmon-mediated magneto-optical transparency

“…Much smaller values of a control magnetic field are feasible if the plasmonic crystal includes magnetic materials, which is referred to as magneto-plasmonic crystal (MPC). Such an MPC provides outstanding magneto-optical properties as evidenced by significant enhancements of the Faraday and transverse Kerr effects192021222324252627282930. The mostly pronounced enhancement of the magneto-optical effects was found for MPCs containing a perforated noble metal stacked on a magnetic dielectric film27282930.…”