Figure 3. Oscillator model for optical and magneto-optical response of magnetic nanoparticle arrays.

The single-particle LSPR in the x (y) direction is composed of m_SPx(y), k_SPx(y) and the damping term γ_SPx(y). The diffracted orders of the array are described by (m, k, γ)_DOy(x), the radiative coupling between the LSPRs and the diffracted orders by k_RADy(x), and the spin–orbit coupling between the two orthogonal oscillators inside the particles by K_SO. We chose our model parameters to mimic the p_x=400 nm, p_y=500 nm sample: in this case the SLR_x resonance is at 600 nm while the SLR_y is at 750 nm.