Optoelectronic Material Characterization Platform using RF Topological Edge States

Abstract

AbstractEfficient characterization of optoelectronic material properties represents a crucial step in the development of next‐generation infrared (IR) materials and devices. For the first time, a sensitive, contact‐free optoelectronic material characterization platform is demonstrated that exploits the unique properties of radio frequency (RF) topological edge states implemented in a topological microstrip waveguide. The topological device is compatible with standard printed circuit board (PCB) processes with no additional materials, stubs, or resonators. The waveguide and topological properties computationally are designed and then experimentally the results are validated with S‐parameter and near‐field measurements. Finally, as a proof of principle, the room temperature spectral response of a micron‐scale thick mid‐wave infrared (MWIR) mercury cadmium telluride (Hg0.70Cd0.30Te) is measured using the topological microstrip and a five‐fold and 20‐fold increase is demonstrated in response when compared to a plain microstrip and trivial bandgap device, respectively. These results open the door to straightforward, low‐cost characterization of optoelectronic films.