Related Experiment Video
Updated: Jul 31, 2025
13:44
Simulation, Fabrication and Characterization of THz Metamaterial Absorbers
Published on: December 27, 2012
15.4K
Thin flexible multi-octave metamaterial absorber for millimeter wavelengths
Applied Optics
|May 3, 2023
Summary
This study introduces a novel metamaterial absorber for millimeter astronomy, achieving over 99% absorbance across 80-400 GHz. This low-profile, ultra-wideband device meets stringent requirements for cosmic microwave background instruments.
Area of Science:
- Metamaterials and Nanotechnology
- Electromagnetics and Optics
- Astronomy Instrumentation
Background:
- Advanced radiation absorbers are crucial for millimeter and submillimeter astronomy, particularly for cosmic microwave background (CMB) instruments.
- Existing absorbers face challenges in achieving ultra-wideband performance, low-profile design, and minimizing optical systematics like instrument polarization.
Purpose of the Study:
- To present a novel metamaterial-inspired flat conformable absorber design for millimeter and submillimeter astronomy.
- To achieve ultra-wideband performance (80-400 GHz) with high absorbance and low polarization for CMB instruments.
Main Methods:
- A metamaterial absorber was designed using subwavelength metal-mesh grids and dielectric layers, employing the magnetic mirror concept.
- An iterative numerical-experimental approach was used for design optimization, with fabrication via a mesh-filter process suitable for cryogenic operation.
- Performance was validated using Fourier transform spectroscopy and vector network analysis in quasi-optical testbeds.
Main Results:
- The absorber demonstrated over 99% absorbance for both polarizations across the 80-400 GHz frequency band, with a minimal difference of 0.2%.
- The device features a low-profile structure with a thickness close to the theoretical limit (quarter wavelength).
- Simulations confirmed angular stability up to ±10 degrees, and the prototype is suitable for cryogenic operation.
Conclusions:
- This work presents the first successful implementation of a low-profile, ultra-wideband metamaterial absorber for the 80-400 GHz range under relevant operating conditions.
- The developed absorber meets and exceeds the demanding specifications for advanced CMB instruments, particularly in reducing optical systematics.
- The fabrication process is scalable and suitable for producing quasi-optical devices for cryogenic applications in radio astronomy.
