with field amplitude ε 0 , carrier frequency ω, phase η, unit vectors êx and êy along the x-and y-axes and shape function s(t) = sin 2 πt tp , with t p the duration of the pulse. We assume the circularly polarized light pulse propagates along the z-axis and that the circular chromophore is oriented perpendicular to the pulse (i.e., aligned with the xy-plane).