Polarization Sensitive Multi-Chroic MKIDs

TL;DR

This paper presents the development of scalable, polarization-sensitive MKID arrays designed for multi-kilo-pixel experiments to study the polarization of the CMB and Galactic dust, featuring dual-band and dual-polarization capabilities.

Contribution

The paper introduces a novel design for multi-chroic, polarization-sensitive MKID arrays with a broadband coupling circuit suitable for large-scale CMB and dust emission observations.

Findings

Electromagnetic simulations indicate 90% absorption efficiency.

Design supports simultaneous dual-polarization and dual-band detection.

Fabrication was scheduled to begin in summer 2016.

Abstract

We report on the development of scalable prototype microwave kinetic inductance detector (MKID) arrays tailored for future multi-kilo-pixel experiments that are designed to simultaneously characterize the polarization properties of both the cosmic microwave background (CMB) and Galactic dust emission. These modular arrays are composed of horn-coupled, polarization-sensitive MKIDs, and each pixel has four detectors: two polarizations in two spectral bands between 125 and 280 GHz. A horn is used to feed each array element, and a planar orthomode transducer, composed of two waveguide probe pairs, separates the incoming light into two linear polarizations. Diplexers composed of resonant-stub band-pass filters separate the radiation into 125 to 170 GHz and 190 to 280 GHz pass bands. The millimeter-wave power is ultimately coupled to a hybrid co-planar waveguide microwave kinetic inductance detector using a novel, broadband circuit developed by our collaboration. Electromagnetic simulations show the expected absorption efficiency of the detector is approximately 90%. Array fabrication will begin in the summer of 2016.