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ABSTRACT (Maximum 200 words)Periodic structures were designed, fabricated and characterized to control the emission of electromagnetic radiation. These electromagnetic crystals were fabricated using interferometric lithography, a technique that lends itself to large area periodic structures. The characterization was done using a Fourier Transform Infra-red Spectrometer. Extensive rigorous modeling was developed based on reigorous coupled-wave analysis and was shown to provide a route to "design-to-performace" for these structures.
WWII 057
AbstractPeriodic structures were designed, fabricated and characterized to control the emission of electromagnetic radiation. These electromagnetic crystals were fabricated using interferometric lithography, a technique that lends itself to large area periodic structures. The characterization was done using a Fourier Transform Infra-red Spectrometer. Extensive rigorous modeling was developed based on rigorous coupled-wave analysis and was shown to provide a route to "design-to-performance" for these structures.Electromagnetic crystals are periodic structures that can be used to control the emission of electromagnetic radiation. The goal of the HIDE program is to directly control the emissivity of an object. The fabrication of the crystals is based on interferometric lithography (see attachment for a description of this method). This is a technique whereby two laser beams are interfered to establish a periodic pattern on a sample. Using standard lithography techniques, the pattern is transferred to the chosen material system. Currently, the material system of choice is silicon on sapphire and bulk silicon. In these material systems, we are able to etch a periodic pattern of air holes in the silicon sample. In addition, the material system can be metallized to obtain higher responsivity in a smaller area. Keep in mind that the system being tested is simply a two-dimensional electromagnetic crystal that is finite in the third dimension. Remarkably, the need for a three-dimensional structure to achieve the desired result is not apparent. We have independently shown that omni-directional stop bands can be achieved using simply a one-dimensional stack of alternating dielectric material. Although a "cute" solution, the utility of such a solution remains to be...