Long-wavelength Nanophotonics

Student’s name: Laney Windlan Home Institution: Florida State University NNCI Site: TNF @ UT Austin REU Principal Investigator: Dr. Daniel Wasserman–Chandra Department of Electrical and Computer Engineering, UT Austin REU Mentor: Noah Mansfield- Chandra Department of Electrical and Computer Engineering, UT Austin Abstract: As Nanophotonic devices continue to advance, reducing their volume becomes a key objective. However, in order to achieve high absorption, considerable thickness is often necessary. Producing thin metal films capable of such absorption can have a variety of applications primarily with detectors and sensors, but accurately fabricating these films is incredibly difficult. Additionally the properties of thin metals often vary greatly from those of their bulk counterparts. To address these issues and create a device with substantial absorption capabilities a three layer metal structure was fabricated. In order to determine the most optimal thicknesses of each layer a Comsol simulation was utilized. We concluded that in order to minimize reflection and therefore maximize absorption a base layer of Gold, followed by an Silicon Dioxide spacer, a layer of Germanium, and a top patterned layer of Gold would be most favorable. We adjusted several variables such as thickness of each layer and the dimensions of our pattern to attain best results. After fabrication was completed we conducted reflection measurements and compared our results to those of the simulation. These promising results offer new insights about the absorption capabilities of thin metal films.