Investigation of Optical Coupling in Microwave Kinetic Inductance Detectors using Superconducting Reflective Plates

Abstract

To improve the optical coupling in Microwave Kinetic Inductance Detectors (MKIDs), we investigate the use of a reflective plate beneath the meandered absorber. We designed, fabricated and characterized high-Q factors TiN-based MKIDs on sapphire operating at optical wavelengths with a Au/Nb reflective thin bilayer below the meander. The reflector is set at a quarter-wave distance from the meander using a transparent Al${}_2$O${}_3$ dielectric layer to reach the peak photon absorption. We expect the plate to recover undetected photons by reflecting them back onto the absorber.

Journal of Low Temperature Physics, Springer Verlag (Germany), In press

References in corpus (2)

• High Quality Factor Platinum Silicide Microwave Kinetic Inductance Detectors
• Sub-Kelvin Thermometer for On-Chip Measurements of Microwave Devices Utilizing Two-Level Systems in Superconducting Microresonators