Photonic bandgap materials:A little history behind photonic bandgap (PBG) materials?In 1987, an American physicist and engineer named Eli Yablonovitch and professor of Canadian physicist from the University of Toronto Canada, Sajeev John built artificial structures that later became the concept of PBG material. To evaluate this concept they created a 3D prototype of a diamond lattice out of Plexiglas, which is a type of acrylic glass material. With this creation they were able to demonstrate that PBG materials are capable of propagating electromagnetic waves. What are Photonic Band Gap (PBG) materials? Photonic Band Gap (PBG) materials, also known as photonic crystals (PC) , have previously been introduced as a way of managing the optical properties of some materials. PBG materials are artificial, dielectrics that have a periodic composition of permittivity. It turned out that we could obtain not only frequency ranges for materials in which light cannot propagate, but also ranges in which light can propagate, these frequencies are also said to be scale-dependent. By decreasing the scale of the unit cell in the periodic lattice, the frequency ranges change, making the values ​​higher. As a result, we are able to alter the structure of the 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 that behave like an isotropic mirror and finally the 3D material in which it behaves as an isotropic mirror for one or more frequency ranges. Metallic gratings have curious properties while in the microwave dom...... at the center of the paper...... Band Gap (PBG) materials. Retrieved from http://www.jpier.org/PIER/pier41/01.0201081.Guida.LP_PI.pdfSouchack, S.M., Lustrac, A., Huynen, I., Talhi, R. Properties of metallic photonic bandgap prism at microwave frequencies: calculation and experimental verification. Retrieved from AngelSajeev John Department of Physics University of Toronto Photonic Band Gap Materials: Engineering the Fundamental Properties of Light. Retrieved from http://cmp.ameslab.gov/PECSVI/ProgramBook/4MondayMorning.pdfSoukoulis, CM (April 1996) Photonic bandgap materials: the “semiconductors” of the future? Retrieved from http://cmp.physics.iastate.edu/soukoulis/publications/171.pdfDowling, P. Jonathan, Bowden, M. Charles (1994) Anomalous index of refraction in photonic band gap materials Retrieved from http:// www .phys.lsu.edu/~jdowling/publications/Dowling94.pdf