This dataset contains data on gold plasmonic nanogratings used for diffraction circular intensity difference spectroscopy. The data was collected to first characterise the various nanogratings studied using atomic force microscopy - the nanogratings show a lattice constant of 1.2 (square-ring and S-shaped) and 2.4 micrometres (L-shaped) respectively. All nanogratings are about 35 nm thick and have an arm width of 200 nm.  Second, circular intensity difference spectroscopy was used to study the chiroptical response of those nanogratings. Strong chiroptical responses were measured from the S- and L-shaped nanogratings. The experimental results were supported by rigorous numerical simulations carried out in Lumerical as well as a Fourier modal analysis. The users who would like to find out more in depth can then refer to the Documentation section