Metamaterial absorber, an artificially material with novel properties paths a route to fabricate device with engineered electromagnetic properties which is hardly achieved by natural material. In this thesis, narrow and broadband infrared absorber from 2D to 3D simulation is presented with discussion of theory and mechanism based on finite difference time domain method (FDTD) and rigorous coupled-wave analysis (RCWA). The Full Width at Half Maximum (FWHM) of designed broadband absorber maintains nearly 4um with strong independency of incident angle and polarization.;Finally, tunable absorber based on hyperbolic metamaterial is introduced to further engineer absorption spectrum which offers potential in military camouflage. |