Fig. 4

Threshold behavior. Total diffracted power divided by pump intensity (indicative of the square of the magnetization order parameter) normalized afterwards to its maximum observed value for each of the structures vs. pump intensity. Red dots: anti-ferromagnetic state at B_z = 0, blue dots: ferri-magnetic state at B_z = 130 mG. The dashed black line indicates a linear fit to the linear range of the curve from 4.2 to 21.24 mW cm⁻². The threshold extrapolated from the intercept with the x-axis is 4.1 mW cm⁻². Other parameters: b₀ = 27, δ = −7Γ, d = −2.9 mm and B_x ≈ B_y ≈ 0