FDTD software: Lumerical (Ansys, version 2021 R2.3). Structure: aluminum (Palik) substrate; 230/260/290/320/350 nm thickness (h) aluminum oxide (Palik) layer with 35 nm diameter (RPo) cylindrical pores with 100 nm distance (D) between the pore centers (representing porous anodized aluminum oxide - PAAO); 60 nm diameter (AgRNP) silver (Palik) nanoparticles (Ag NPs) placed directly above each pore; 60 nm thickness (DLC) layer with experimentally obtained optical properties of diamond-like carbon (DLC). Ag nanoparticles are encapsulated in DLC. DLC optical properties are averaged result of the matrix properties in DLC:Ag nanocomposite obtained by fitting spectroscopic ellipsometry data, which is available here: https://doi.org/10.5281/zenodo.7341684 The file used in the simulations is provided in this data set. Refractive index of the surrounding medium (n): 1.0; 1.1; 1.2; 1.3. Simulation region: from 300 nm below the substrate/PAAO interface to 1.3 µm above PAAO surface; x and y spans are equal to one period of the structure. Mesh override region: from 50 nm below the PAAO to 50 nm above DLC:Ag; 2 nm step size in each direction. Light source: BFAST plane wave light source; 500 nm above PAAO; 45° angle of incidence (ang); 300 nm – 1000 nm wavelength range; p-polarization (pol). Monitor (frequency domain field and power): 2D Z-normal; 1 µm above PAAO; results are in "_reflection.txt" files. Information in the file name: h - thickness of PAAO; AgRNP - diameter of silver nanoparticles; DLC - thickness of DLC; pol - polarization; RPo - diameter of pores; D - distance between pore centers; ang - angle of incidence; n - refractive index of surrounding medium. Files: (1) "_reflection.txt" - lambda(nm) (first column) - wavelength in nanometers; Y (second column) - T data from the monitor above the structure. (2) "_p0.log" - log file produced by the software while running the simulation. (3) ".fsp" - Lumerical software file containing the simulation project (license required to open these files). (4) "Lumerical_Screenshots.pdf" - shows software screenshots for every object and its every property; red text is added to show which values are different for different simulations. (5) "Structure_Illustration.jpg" - a schematic of modeled structure. (6) ".jpg" - a preview of data from "_reflection.txt" files. (7) "DLC_SE_nk_average.txt" - contains DLC optical properties (first column - wavelength in nanometers; second column - refractive index; third column - extinction coefficient).

The research was carried out under postdoctoral project "Patterned hybrid multilayer films for optical sensors", No. 1.1.1.2/VIAA/4/20/615.