We numerically and analytically report an ultra-broadband near perfect absorber based on one-dimensional metal-dielectric-metal grating at visible light for TM polarization. A unit cell of this design is composed of metal-dielectric-metal grating, where the bottom metallic layer and the upper metallic coating are separated from each other by the intermediate dielectric grating. The absorber exhibits an average absorption of over 90% in the range 400-700nm. Moreover, they remain very high over a wide range of incident angle up to 45°.The electromagnetic field distributions are investigated, which reveals that this broadband absorption behavior is ascribed to the combination of surface plasmon resonance and cavity resonance. Furthermore, impedance calculations were carried out to explain the absorption behavior. The ultra-broadband near-perfect angle-robust absorber can be a good candidate for many fascinating applications, including solar-energy harvesting as well as producing artificial colors on a large scale substrate.

Date Published: 25 October 2016
PDF: 6 pages
Proc. SPIE 10158, Optical Communication, Optical Fiber Sensors, and Optical Memories for Big Data Storage, 1015809 (25 October 2016); doi: 10.1117/12.2244269

Published in SPIE Proceedings Vol. 10158:
Optical Communication, Optical Fiber Sensors, and Optical Memories for Big Data Storage