Journal of Theoretical and Applied Physics (JTAP) On the discrete dipole approximation investigation of the extinction spectra of Ag/glass nano-flower thin film with threefold symmetry Volume 6 (2012) Issue 1, November and December 2012 2023 11 17 On the discrete dipole approximation investigation of the extinction spectra of Ag/glass nano-flower thin film with threefold symmetry 10.1186/2251-7235-6-4 EN Fatemeh Abdi Department of Physics, University of Tehran Araz Siabi-Gerjan Department of Physics, University of Tehran Hadi Savaloni School of Physics, College of Science, University of Tehran, North‑Kargar Street, Tehran, Iran 0000-0002-6836-106X Journal Article 2023 11 17 AbstractThe use of glancing angle deposition technique provides opportunities for the deposition of sculptured nanostructures of different shape. The optical properties of such nanostructures that are a function of the shape of these nanostructures may be investigated, using the discrete dipole approximation theory which is an appropriate method for solving the light scattering problem from objects of different shape and geometry. In this paper, the extinction spectra of Ag/glass-sculptured nano-flowers with threefold symmetry are modeled and calculated, while the results are compared with similar experimental observations. In modeling the nano-flower-shaped sculptured thin films, it is proposed that the nano-flower is formed as a combination of two chiral thin films with different dimensions. This structure was replaced with 1,405 electrical dipoles, and its extinction spectrum was calculated as a function of incident light angle and azimuthal angle. The extinction spectrum consists of both transverse and longitudinal modes of oscillations. The results showed that by increasing the incident angle, due to increase of amplitude of electrical oscillations, transverse oscillations shift towards longer wavelengths. It was also observed that at azimuthal angles close to nano-flower petals, where sharp points or recesses may exist, the intensity of extinction spectrum for longitudinal mode (long wavelengths in the extinction spectrum) increases.