Epsilon-near-zero (ENZ) materials host exotic nonlinear optical effects which enable broadband responses[1] while only requiring small interaction lengths[2]. Such capabilities have made ENZ materials promising candidates for hosting nonlinear optical processes on photonic chip environments. The nature of these responses specific to the ENZ regime stem largely from polarization-dependent field enhancements on the ENZ structure’s boundary. In order to characterize such ENZ responses on small length scales, sub-wavelength hole structures were fabricated in ENZ films, which were then inspected using tightly focused structured light beams. Using structured light allows one to tailor the polarization response of the ENZ hole. Therefore, one can equip a polarization state which either maximizes the ENZ field enhancement or completely minimizes it. While drastic polarization-dependent effects can be experimentally observed, additional effects resulting from fabrication errors suggest some limits to experimentally achieving strong ENZ responses. In this progress report, I will give a summary of the work done so far to observe and minimize these unwanted effects, while also touching on a current project which aims to extract local complex refractive index information from modified areas of nano-fabricated ENZ films.
[1] Alam, M. Z., Schulz, S. A., Upham, J., De Leon, I., & Boyd, R. W. (2018). Large optical nonlinearity of nanoantennas coupled to an epsilon-near-zero material. Nature Photonics, 12(2), 79-83.
[2] Reshef, O., De Leon, I., Alam, M. Z., & Boyd, R. W. (2019). Nonlinear optical effects in epsilon-near-zero media. Nature Reviews Materials, 4(8), 535-551.
Zeit: Montag, 28.11.2022, 17:00 Uhr
Ort: HS 05.01
LV: 653.122 - Dissertant*innen Seminar (Experimental- und Festkörperphysik) - Banzer/Hohenester