An ultra-thin isotropic metamaterial thermal radiator
Department of Physics and Materials Science, City University of Hong Kong - Tat Chee Avenue, Kowloon Tong, Hong Kong
2 Applied Optics Beijing Area Major Laboratory, Department of Physics, Beijing Normal University Beijing 100875, China
3 State Key Laboratory of Millimeter Waves, City University of Hong Kong - Tat Chee Avenue, Kowloon, Hong Kong
Accepted: 3 September 2011
We design an ultra-thin infrared metamaterial thermal radiator which has nearly isotropic emission pattern for a wide range of angles. Our design is achieved by overlapping both the electric and magnetic resonances in the spectral domain and is insensitive to both TE and TM polarizations. The thermal emission of the metamaterial is nearly isotropic in which the deviation in the angular emissivity is within 10% up to an angle of 75 degrees at the resonating wavelength of 2.86 μm. Moreover, our metamaterial can be easily scaled to have different resonating wavelengths for efficient radiative cooling or thermal emission at different temperatures.
PACS: 44.40.+a – Thermal radiation / 78.67.Pt – Multilayers; superlattices; photonic structures; metamaterials / 78.20.Ci – Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
© EPLA, 2011