Antenna-coupled TES bolometer arrays for CMB polarimetry

TL;DR

This paper details the design and performance of polarization-sensitive antenna-coupled TES arrays for CMB experiments, highlighting their high efficiency, precise beam control, and spectral band definition for accurate polarization measurements.

Contribution

It introduces a fully lithographic, microstrip-filtered antenna array architecture for TES bolometers, optimized for multiple CMB observation bands with high optical efficiency.

Findings

High optical efficiency and well-defined spectral bands.

Low cross polarization response and well-matched beams.

Development for 100 GHz and 150 GHz bands.

Abstract

We describe the design and performance of polarization selective antenna-coupled TES arrays that will be used in several upcoming Cosmic Microwave Background (CMB) experiments: SPIDER, BICEP-2/SPUD. The fully lithographic polarimeter arrays utilize planar phased-antennas for collimation (F/4 beam) and microstrip filters for band definition (25% bandwidth). These devices demonstrate high optical efficiency, excellent beam shapes, and well-defined spectral bands. The dual-polarization antennas provide well-matched beams and low cross polarization response, both important for high-fidelity polarization measurements. These devices have so far been developed for the 100 GHz and 150 GHz bands, two premier millimeter-wave atmospheric windows for CMB observations. In the near future, the flexible microstrip-coupled architecture can provide photon noise-limited detection for the entire frequency range of the CMBPOL mission. This paper is a summary of the progress we have made since the 2006 SPIE meeting in Orlando, FL.