Control of absorption properties of MEMS terahertz bolometers using metamaterials

We have investigated terahertz (THz) metamaterial absorbers to achieve narrowband absorption properties for microelectromechanical (MEMS) THz bolometers in order to have better matching with the illumination by quantum cascade lasers in THz imaging applications. We have found that metal-insulator-metal (MIM) sandwich structure is crucial to achieve a large THz absorption. The absorption depends on the thickness (h) of the insulator layer. The maximum absorption reached 88% at around 3 THz when
$\mathrm{h}=1400\ \text{nm}$
. The observed absorption spectrum was in good agreement with theory.