It seems that a functional group having a significant dipole moment change, such as the imide group, has a large coupling efficiency even if the molecular number density present in the region/volume is small. If the functional group has a small dipole moment change, such as a CH bond, a large bonding efficiency also can be obtained when the number of functional groups is also large. The question is, how these modes of molecular species correspond to each other. To clarify this, the modal analysis of molecular vibrations was carried out. Based on the results, the number N of the functional groups of molecules present in the polymer layer just below the nanodisk in the metasurface was estimated. The square root of the product of the integral of absorbance A value and N was determined as the coupling efficiency. This analysis was carried out for strong coupling case, when many modes can be coupled in the cavity, the separation width is replaced by √ N. The results of the analysis are shown in Fig. . Unlike the binding efficiency shown in Fig. , the Fig. shows results where all peaks are sorted along the same line. Although the molecular properties were not entirely known, it was rewarding to see that consistent results were obtained for different molecular species and vibration modes. Although the relationship between the number of dipoles and the number of resonators has been discussed theoretically , few experimental results have been reported.