Resonant Plasmonic Structures for Spintronic THz Emitters

The laws of amplification of electromagnetic fields in thin ferromagnetic films due to the local surface plasmon resonance have been investigated for structures of spintronic THz emitters. The optimal parameters of Pt/Co and Pt/Co/W plasmonic structures, providing maximum optical absorption in the films at a wavelength of 800 nm, have been determined using numerical simulation. The results show that the use of plasmonic structures makes it possible to increase the optical absorption in Pt/Co and Pt/Co/W structures to 25 and 18%, respectively. The structures are found to have high polarization sensitivity, which manifests itself in high absorption anisotropy, equal to 0.9.