Pushing the Limits of Broadband and High-Frequency Metamaterial Silicon Antireflection Coatings
Abstract
Broadband refractive optics realized from high-index materials provide compelling design solutions for the next generation of observatories for the cosmic microwave background and for sub-millimeter astronomy. In this paper, work is presented which extends the state of the art in silicon lenses with metamaterial antireflection coatings toward larger-bandwidth and higher-frequency operation. Examples presented include octave bandwidth coatings with less than 0.5% reflection, a prototype 4:1 bandwidth coating, and a coating optimized for 1.4 THz. For these coatings, the detailed design, fabrication and testing processes are described as well as the inherent performance trade-offs.
- Publication:
-
Journal of Low Temperature Physics
- Pub Date:
- December 2018
- DOI:
- 10.1007/s10909-018-1955-7
- arXiv:
- arXiv:1804.08368
- Bibcode:
- 2018JLTP..193..876C
- Keywords:
-
- Optics;
- Metamaterials;
- Cosmic microwave background;
- Astrophysics - Instrumentation and Methods for Astrophysics;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- doi:10.1007/s10909-018-1955-7