Optimization of a quasi-mesh absorber for the terahertz intensity mapper

Abstract

We discuss the design and optimization of the absorber for the long-wavelength arm of the Terahertz intensity mapper, a balloon-borne spectrometer employing kinetic inductance detectors. Electromagnetic simulations of our design indicate in-band absorption efficiency over ∼! 80% in both linear polarization modes. By developing custom transmission line model and mode-matching calculations, we find the absorption efficiency is affected by the absorber's reactive part and overall shape. These insights into the operation of this design provide guidance for its optimization for low-resistance absorber materials.