File name is "number of layers"_"films or nanoparticles"_"number of examples" for thicknesses without "val" and for spectrum with "val".
For example, "8layer_films_50000" means that there are 50000 examples, each representing the thicknesses of 8-layer films.
"8layer_films_50000_val" representes the corresponding transmission spectrum from 400 nm to 800nm with 2nm step (not including 800 nm).