Perfectly-Absorbing Photoconductive Metasurfaces for High Efficiency Ultrafast Optoelectronic Switches

Current methods applied to terahertz detectors and generators are fundamentally restrictive due to the approaches they employ and the material system they use. This directly affects the efficiency of the resulting terahertz detectors and generators. There is a single fix to the current issues in terahertz detectors and generator technology by use of a novel materials system, Mercury-Cadmium-Telluride, in combination with nano structured metasurface which leads to multifold improvement in device efficiency. The Phase I effort is aimed at formulating computer model of the material system and the said nanostructured metasurface to optimize the device geometry as well as demonstrating the feasibility of such a device by fabricating the prototype of the optimized geometry and related terahertz testing results on the prototype device. Mercury-Cadmium-Telluride metasurface-based photoconductive terahertz detectors and generators will find applications in a wide variety of fields as follows: Terahertz sources and detectors will be used in biomedical imaging applications for the purpose of cancer imaging, burn wound assessment and dental tissue imaging. Commercial applications, such as, nondestructive screening of pharmaceuticals, spectral fingerprinting of chemical compounds is also envisioned. Spectral fingerprinting is also useful in security applications such as, nondestructively detecting hidden narcotics and explosives. Terahertz imaging and time-domain reflectometry will be used as a quality control tool in industrial establishment such as electronics fabrication and packaging as well as composite material inspection. Terahertz generators and detectors are also in demand for use in scientific research laboratories.