The textbook "Optical Properties of Bismuth-Based Topological Insulators" by Paola Di Pietro provides a comprehensive examination of the optical properties of bismuth-based topological insulators (TIs). These materials are characterized by their insulating properties in the bulk while exhibiting exotic metallic states at the surface. The work employs infrared spectroscopy to analyze the optical conductivity in the low-energy range and to distinguish the extrinsic charge contributions from the volume from the intrinsic contributions of the surface state carriers. The results demonstrate the two-dimensional nature of the carriers in these materials. Additionally, the experimental setups, the FTIR technique, the theoretical foundations of the optical properties, and the methods for sample preparation of crystals and thin films are described in detail.