Photonic bandgap materials:A little history behind photonic bandgap (PBG) materials? In 1987, an American physicist and engineer named Eli Yablonovitch and Canadian physics professor from the University of Toronto Canada, Sajeev John built artificial structures which later became the concept for the PBG material. To evaluate this concept, they created a prototype 3D diamond array made of Plexiglas, a type of acrylic glass. With this creation, they were able to prove that PBG materials are capable of propagating electromagnetic waves. What are photonic band gap (PBG) materials? Photonic bandgap (PBG) materials, also known as photonic crystals (PCs), were once introduced as a photonic bandgap (PBG) material. way to manage the optical properties of certain materials. PBG materials are artificial dielectrics that have a periodic permittivity composition. It was found that we could not only obtain frequency ranges for materials in which light cannot propagate, but also ranges in which light can propagate, these frequencies are also considered to be scale dependent . Decreasing the scale of the unit cell in the periodic network causes the frequency ranges to change, thereby increasing the values. As a result, we are able to modify the design of a photonic crystal from the microwave range to the visible or infrared range. There are 3 band structures (Fig. 1), the 1D, the 2D and the 3D, in which the 1D material has only one ideal direction of wave propagation, the 2D material with 2 ideal directions which behave like an isotropic mirror and finally the 3D material in which behaves like an isotropic mirror for one or more frequency ranges. Metallic lattices have curious properties in microwave dom...... middle of paper...... Band Gap (PBG) materials. Retrieved from http://www.jpier.org/PIER/pier41/01.0201081.Guida.LP_PI.pdf Souchack, SM, Lustrac, A., Huynen, I., Talhi, R. Properties of metallic photonic bandgap prism at frequencies microwaves: calculation and experimental verification. Excerpted from AngelSajeev John Department of Physics University of Toronto Photonic bandgap materials: engineering the fundamental properties of light. Retrieved from http://cmp.ameslab.gov/PECSVI/ProgramBook/4MondayMorning.pdfSoukoulis, CM (April 1996) Photonic Band Gap Materials: The “Semiconductors” of the Future? Retrieved from http://cmp.physics.iastate.edu/soukoulis/publications/171.pdfDowling, P. Jonathan, Bowden, M. Charles (1994) Anomalous refractive index in photonic bandgap materials Retrieved from http:/ /www.phys.lsu.edu/~jdowling/publications/Dowling94.pdf