A wide-angle and polarization insensitive highly-tunable infrared metamaterial perfect absorber

A highly-tunable wide-angle metamaterial absorber with perfect absorption and polarization-insensitivity was introduced and investigated. Simulative results show the maximum absorption reaches up to 99.9% at 5.8 (mu)m and the absorber can be tuned arbitrarily in the range of 3.4 (mu)m to 8.6 (mu)m with the absorption remaining above 95% by changing its geometric parameters. The absorber remains absorptivity of over 95% with incident angles below 80 degree under transverse magnetic (TM) polarization and that of over 92% below 60 degree under transverse electric (TE) polarization. Furthermore, the absorber is polarization insensitive with polarization angle varying from 0 degree to 90 degree .