Surface plasmon resonance: omega_SPR = omega_p/sqrt(1 + eps_d); complex pole

Surface-plasmon-resonance dispersion framework (Ritchie 1957 Phys Rev 106, 874; Raether 1988). Setup: at flat metal-dielectric interface, EM waves propagate as bound SPPs with k_SPP = (omega/c) sqrt(eps_m eps_d/(eps_m + eps_d)).…