Figure 4
Power dependence. Power dependent measurements of the transparency signals. The signals shown are obtained by subtracting the background absorption spectrum (subtracting the referring spectra of Fig. 2). Examined is the dependency of the signals on the power ratio between probe and coupling laser. (a) Illustrates the dependency of the signals to the power of the coupling beam, while the probe beam is fixed to a power of 3 μW. Here a change of the width of all peaks and as well of all splittings between the peaks is observed; this holds for both features originating from F = 1 and F = 2. Subfigure (b) Shows the signal’s dependence on the power of the probe beam, while the coupling power is fixed to a power of 450 mW. Here no change of the width of the center peaks or the splitting between the side peaks is observed. The (green) signal in both measurements can be compared, they are measured at comparable powers. All the signals are normalized to the same value (maximum transmission of the green curve in (a)) and can hence be qualitatively compared in height. The peaks beside the main peaks form the anti crossings, visible in Fig. 3.
