Figure 6

VRS of a locked versus an unlocked cavity The plot shows the averaged transmitted intensity of the probe versus detuning of the probe light from \(F={3}\)-3′ transition of ⁸⁵Rb under collective strong coupling condition. The two peak structure VRS is obtained by scanning the probe laser around the atomic transition. Fig. (a), Fig. (b), and Fig. (c) are plotted by taking the averages of the data from 0–10, 45–55, and 90–100 respectively. The symmetric VRS peak shown in Fig. (d) is obtained when there is an active stabilization on the length of the cavity. In the unlocked case, during the measurement, the resonant frequency of the optical cavity changes due to the drift and fluctuations in the length, as a result, the expected symmetry in the double-peak structured VRS is lost