Abstract-THz characterization and demonstration of visible-transparent/terahertz-functional electromagnetic structures in ultra-conductive La-doped BaSnO3 Films

Sara Arezoomandan, Abhinav Prakash, Ashish Chanana, Jin Yue, Jieying Mao, Steve Blair, Ajay Nahata, Bharat Jalan,  Berardi Sensale-Rodriguez

https://www.nature.com/articles/s41598-018-22038-w

We report on terahertz characterization of La-doped BaSnO3 (BSO) thin-films. BSO is a transparent complex oxide material, which has attracted substantial interest due to its large electrical conductivity and wide bandgap. The complex refractive index of these films is extracted in the 0.3 to 1.5 THz frequency range, which shows a metal-like response across this broad frequency window. The large optical conductivity found in these films at terahertz wavelengths makes this material an interesting platform for developing electromagnetic structures having a strong response at terahertz wavelengths, i.e. terahertz-functional, while being transparent at visible and near-IR wavelengths. As an example of such application, we demonstrate a visible-transparent terahertz polarizer.