114. METASURFACE BASED MICRO-PLASMA DEVICES
Name: Shiva Piltan
Grad Year: 2017
Plasma devices offer several benefits compared to their counterparts using semiconductors as the conducting channel. The self-healing property of plasma makes it more resilient to environmental conditions including overvoltage and radiation. In addition, gas plasma is potentially faster and capable of handling higher powers. However, plasmas are susceptible to instabilities, in particular arcing. One approach to sustaining stable plasma in atmospheric pressures is confining the dimensions to below 1mm cavities to lie within a certain range of pressure-distance product. There are several challenges including ignition and confinement of plasma, and packaging of the devices. The proposed metasurface based micro-plasma device integrates the benefits of micro-plasma with the combination of DC and laser induced discharges using the electromagnetic resonance. The key element of the metasurface based device is the enhancement of electric field due to the resonance which increases the interaction of the wave with matter. A similar phenomenon occurs in surface-enhanced Raman scattering where the fissures in the rough surface act as high Q optical cavities. The inherent resonance frequency of the designed periodic structure depends on the geometry. The metasurface is DC biased at a much lower voltage than conventional micro-plasma devices and excited by a low-power optical field corresponding to the resonance frequency of the surface. The combination of the laser-induced and DC breakdown, reduces both the required voltage and laser power to ignite the plasma. Furthermore, due to the coupling between the unit-cells sharing the same gas, the plasma may spread over the surface making the device scalable to higher powers. The surface consists of an array of metallic resonant structures fabricated on a SiO2 substrate with a resolution of 100nm. The geometry is designed such that the maximum field enhancement at a certain frequency occurs in the desired spot. The fabrication process includes one stage of ebeam lithography and evaporation of gold. We are currently characterizing the device with optical and surface enhanced Raman scattering measurements.
Industry Application Area(s)
Aerospace, Defense, Security | Electronics/Photonics