A Broadband Micro-machined Far-Infrared Absorber

TL;DR

This paper reports on a broadband far-infrared meta-material absorber with high absorptance over 1-20 THz, demonstrating temperature stability and compatibility with micro-machining, supported by a transmission line model.

Contribution

It introduces a novel broadband meta-material absorber for far-infrared frequencies that is insensitive to geometry and compatible with micro-machining.

Findings

Achieves >0.95 absorptance from 1-20 THz

Operates effectively from 5-300 K

Compatible with silicon-based micro-machining

Abstract

The experimental investigation of a broadband far-infrared meta-material absorber is described. The observed absorptance is $>\,0.95$ from ${\rm 1-20\,THz}$ (${\rm 300-15\,\mu m}$) over a temperature range spanning ${\rm 5-300\,K}$. The meta-material, realized from an array of tapers ${\rm \approx 100\,\mu m}$ in length, is largely insensitive to the detailed geometry of these elements and is cryogenically compatible with silicon-based micro-machined technologies. The electromagnetic response is in general agreement with a physically motivated transmission line model.