2025/06/03 by Wance Wang, Dhruv Fomra, Wang, Wance +7 · 2 citations
Engineering · Physics and Astronomy · #Photonic and Optical Devices #Advanced Fiber Laser Technologies #Optical Network Technologies
paper · pdf · doi:10.48550/arxiv.2506.02501
Transparent conductive oxides (TCO) enable confinement of charge-sensitive ions and Rydberg atoms proximal to dielectric structures including waveguides and photon detectors. However, optical loss precludes the use of TCOs within high-finesse optical micro-resonators. Here we characterize a ZnO-based TCO that markedly reduces optical absorption. At 1650 nm we observe a 22,000 finesse in a Fabry-Pérot optical cavity coated with a 30 nm ZnO layer. This is a 5000 times reduction relative to indium tin oxide (ITO) at this wavelength. The same ZnO film exhibits 0.01\text \ensuremathΩ\ensuremath⋅cm surface resistivity at DC. We anticipate a step change in cavity-QED systems incorporating ultra-low loss TCOs like ZnO.