Demonstration of Ultra-Sensitive KIDs for Future THz Space Borne Polarimeters

TL;DR

This paper demonstrates the high polarization purity and sensitivity of microwave Kinetic Inductance Detectors (KIDs) at 1.5 THz, showing their potential for future space-based polarimetric instruments.

Contribution

It provides experimental measurements and simulations of KID polarization purity and sensitivity, advancing their application in space-borne THz polarimetry.

Findings

Cross-polarization level at -21.5 dB for 1 fλ sampling

Measured noise equivalent power of 5-7×10⁻²⁰ W/√Hz

Good agreement between measurements and theoretical models

Abstract

We present measurements and simulations of the polarization purity of leaky lens-antenna coupled microwave Kinetic Inductance Detectors (KIDs) at 1.5 THz. We find the integrated cross-polarization level to be at -21.5 dB for 1 f\#$\lambda$ spatial sampling. The measurements agree well with the theoretical description which is based on a combination of in-transmission simulation of the antenna feed, and an in-reception analysis of the antenna-KID system. Combined with the measured noise equivalent power of 5--7$\times$10$^{-20}$ W/$\sqrt{\mathrm{Hz}}$, these detectors are excellent candidates for large scale and high performance imaging polarimetric instruments.