Ultrabroadband light absorption by a sawtooth anisotropic metamaterial slab

• Main Authors: Cui, Yanxia (Author), Fung, Kin Hung (Contributor), Xu, Jun (Contributor), Ma, Hyungjin (Author), Jin, Yi (Author), He, Sailing (Author), Fang, Nicholas Xuanlai (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Mechanical Engineering (Contributor)
• Format: Article
• Language: English
• Published: American Chemical Society (ACS), 2013-04-11T16:19:00Z.
• Subjects: Article
• Online Access: Get fulltext

We present an ultrabroadband thin-film infrared absorber made of sawtoothed anisotropic metamaterial. Absorptivity of higher than 95% at normal incidence is supported in a wide range of frequencies, where the full absorption width at half-maximum is about 86%. Such property is retained well at a very wide range of incident angles too. Light of shorter wavelengths are harvested at upper parts of the sawteeth of smaller widths, while light of longer wavelengths are trapped at lower parts of larger tooth widths. This phenomenon is explained by the slowlight modes in anisotropic metamaterial waveguide. Our study can be applied in the field of designing photovoltaic devices and thermal emitters.
National Science Foundation (U.S.) (CMMI 0846771)
National Natural Science Foundation (China) (60990320)
National Natural Science Foundation (China) (60901039)