Photonic Band Gap Materials:

A little history behind Photonic Band Gap materials (PBG)?
In 1987, an American physicist and engineer named Eli Yablonovitch and Canadian physics professor from the University of Toronto Canada, Sajeev John constructed artificial structures that then became the concept of PBG material. In order to evaluate this concept they created a 3D prototype diamond lattice in Plexiglas, which is a type of acrylic glass material. With this creation they were able to prove that PBG materials are capable of propagating electromagnetic waves.
What are Photonic Band Gap materials (PBG)?
Photonic band gap materials (PBG), also known as photonic crystals (PC), were formerly introduced as a way to manage the optical properties of certain materials.
PBG materials are artificial, dielectrics that have a periodic composition of permittivity.
It was discovered that we could not only obtain frequency ranges for materials which light cannot propagate but also ranges in which light can propagate, these frequencies also said to be scale dependent. Diminishing the scale of the elementary cell in the periodic lattice causes the frequency ranges to change, making there values higher. As a result of this, we are able to alter a photonic crystal design from the microwave range into 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 as an isotropic mirror and finally the 3D material in which behaves as an isotropic mirror for one or more frequency ranges.
Metallic lattices have curious properties while in the microwave dom...
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... Band Gap (PBG) materials. Retrieved from http://www.jpier.org/PIER/pier41/01.0201081.Guida.LP_PI.pdf
Souchack, S.M. , Lustrac, A. , Huynen, I. , Talhi, R. Properties of Metallic Photonic Band Gap Prism at microwave frequencies: calculation and experimental verification. Retrieved from Angel
Sajeev 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.pdf
Soukoulis, C. M. (April, 1996) Photonic Band Gap Materials: The “Semiconductors” of the Future? Retrieved from http://cmp.physics.iastate.edu/soukoulis/publications/171.pdf
Dowling, 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
For the E primer sets, there are two strong bands. Around the 1018 MWM bands which approximately cor...
In 1895, Professor Wilhelm C. Roentgen, a German physicist, was working with a cathode ray tube, much like our fluorescent light bulb. The tube consisted of positive and negative electrodes encapsulated in a glass envelope. On November 8, 1895, Roentgen was conducting experiments in his lab on the effects of cathode rays. He evacuated all the air from the tube and passed a high electric voltage through it after filling it with a special gas. When he did this, the tube began to give off a fluorescent glow. Roentgen then shielded the tube with heavy black paper and discovered a green colored fluorescent light could be seen coming from a screen located a few feet away from the tube.
Tseng, C. C.; Ding, H. F.; Li, A.; Guan, Y. C.; Chen, D. Y.K. Org. Lett., 2011, 13, 4410.
early 1990’s, no such material was known. In 1991, carbon nanotubes were discovered. Although not
The index of refraction is defined as the speed of light in vacuum divided by the speed of light in the medium. In this experiment, the index of refraction for the perspex is 1.50. Snell's Law relates the indices of refraction of the two media to the directions of propagation in terms of the angles to the normal. It refers to the relationship between the different angles of light as it passes from one transparent medium to another. When light passes from one transparent medium to another, it bends according to Snell's law which states: [IMAGE] where: n1 is the refractive index of the medium the light is leaving, n2 is the refractive index of the medium the light is entering, sin 2 is the is the incident angle between the light ray and the normal to the medium to medium interface, sin 1 is the refractive angle between the light ray and the normal to the medium to medium interface.
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Kennedy, Gerry. "The Spectronics Blog." The Spectronics Blog RSS. Spectronicsinoz, 15 May 2012. Web. 04 Mar. 2014.
Asyie, Gul. “Hybrid Polymer Gamma Ray Shielding Material”. Can Lasers A.S. Can Lasers A.S. Web. 13 Nov 2013.
waves are further divided into two groups or bands such as very low frequency (
Refraction is a process that occurs when light travels between media of different optical density. Light travels at a speed of roughly 3.0 × 108ms-1 in a vacuum. A vacuum has a refractive index n=1.00. The speed at which the light is travelling will decrease as it moves into differently optically
Grundmann, Marius. Physics of Semiconductors: An Introduction Including Devices and Nanophysics. New York: Springer, 2006. Print.
The photovoltaic effect, electricity can be created directly from sunlight. Some semi-conductor materials that are exposed to sunlight can create electron-hole pairs, which can be collected to produce electricity. This occurs when photons have energy above a certain threshold. These photons have shorter wavelengths. In silicon, the threshold for electron-hole production is in the infrared region of the electromagnetic spectrum.