Fig. 4: Extended analysis of dichroism and birefringence as a function of probe polarization and wavelength.

a, Extracted transient complex index for a probe polarized in the x direction (red curves) and in the y direction (blue curves) for a horizontally polarized pump (see descriptive icons). b, Power coupling efficiency into the 900-nm AZO film against wavelength for pumped (orange dotted-dashed line) and unpumped (blue solid line) cases. c, Imparted probe polarization rotation (Δθ_c) and ellipticity as a function of probe wavelengths at maximum temporal overlap. Probe polarization is set at 45° with respect to the horizontal pump, as shown in descriptive icon. d, Decoupling parameter between dichroism and birefringence for different probe wavelengths. Formula for decoupling parameter d_c is shown in inset with φ_bi being the nonlinear birefringence phase shift. At wavelengths above the film’s ENZ crossover, the maximum achievable dichroism diminishes much faster than the birefringence, allowing these two effects to be partially decoupled.