Nanopatterned Phase Change Material for Mid-Infrared Tunable Optical Filters using Germanium Antimony Telluride

Date of Award


Degree Name

M.S. in Electro-Optics and Photonics


Department of Electro-Optics and Photonics


Imad Agha


Material characteristics and crystallinity of germanium antimony telluride (GST) using various design methods for simulation and fabrication are presented. Experimental verification of designs in the mid-infrared are presented for GST-Ag structures and amorphous-crystalline GST structures. Baking an amorphous state GST sample at 200 degrees for 2 minutes will produce a crystalline state GST which causes the refractive index to increase significantly. Gradually increasing the temperature of an annealed phase change material, such as GST, controls the amount of crystallinity which allows the index of refraction to increase continuously over a significant range. Changing the amorphous state optically allows a lithography-free grating device. The use of GST in these metasurface structures uncovers unique properties that cover transmittance of devices, diffraction orders and tunable optical filters that are angular independent.


Optics, Electromagnetics, Design, Physics, GST germanium antimony tellurise phase change material pcm optical filter tunable

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