1. 'Fig1_AGFM.xlsx' AGFM measured results of 10 nm thick ASI sample with 0° and 45° magnetic fields are shown in Figs.1 (a) and (b) 2. 'Fig1_MH_MuMax.xlsx' Figure 1 shows the MH curves of the independent islands at 1° (H1), 89°(H89), 43°(H43) and 47°(H47) magnetic fields are calculated using MuMax package. The average magnetization curve of H1 and H89 magnetization are also computed in order to compare with that of 5×5 island array. In addition, the average magnetization curve of H43 and H47 magnetization are also calculated, as shown in Fig.1 (c). 3. 'Fig2_BLS_DE_Spectra.xlsx' This file includes the experimental BLS spectra with the Damon Eshbach configuration (light wavevector is perpendicular to applied field) at 0° and 45° magnetic fields, which are presented in the Figs.2 (a) and (b). The frequencies of spin-wave peaks in Figs.2 (a) and (b) as a function wavenumber are displayed in Fig.2 (c) and (d). 4. 'Fig2_BLS_BA_Spectra.xlsx' This file includes the experimental BLS spectra of the backward configuration (wavevector is aligned parallel to applied field) at 0° and 45° magnetic fields, which are presented in the Figs.3 (a) and (b). The frequencies of spin-wave peaks in Figs.3 (a) and (c) as a function wavenumber are displayed in Fig.3 (c) and (d). 5. 'BLS_SW_frequency.xlsx.' This file contains the measured spin-wave (SW) frequencies vs magnetic field, which are presented in Fig.4 (a) and Fig.5 (a) 6. 'Fig4_SWmode_frequency_MuMax.xlsx' + 'Fig5_SWmode_frequency_MuMax.xlsx' These two files include the simulated spin-wave frequency as a function of magnetic field for the independent H1 (H43) and H89 (H47) islands, as shown in Fig.4(5) (a). Calculate the out-plane magnetization mz at every ps in MuMax. Resonance frequency and intensity can be obtained by calculating Fourier transform of mz. Using independent island in the micromagnetic simulation is able to extrate the spin wave excitations of two groups of ASI islands from the complex field-dependent ASI spin waves.