Microwave absorptions of ultrathin conductive films and designs of frequency-independent ultrathin absorbers
Sucheng Li,
Shahzad Anwar,
Weixin Lu,
Zhi Hong Hang,
Bo Hou,
Mingrong Shen,
Chin-Hua Wang
Affiliations
Sucheng Li
School of Physical Science and Technology, Soochow University, 1 Shizi Street, Suzhou 215006, China
Shahzad Anwar
School of Physical Science and Technology, Soochow University, 1 Shizi Street, Suzhou 215006, China
Weixin Lu
School of Physical Science and Technology, Soochow University, 1 Shizi Street, Suzhou 215006, China
Zhi Hong Hang
School of Physical Science and Technology, Soochow University, 1 Shizi Street, Suzhou 215006, China
Bo Hou
School of Physical Science and Technology, Soochow University, 1 Shizi Street, Suzhou 215006, China
Mingrong Shen
School of Physical Science and Technology, Soochow University, 1 Shizi Street, Suzhou 215006, China
Chin-Hua Wang
Institute of Modern Optical Technologies & Collaborative Innovation Center of Suzhou Nano Science and Technology, Jiangsu Key Lab of Advanced Optical Manufacturing Technologies, Soochow University, 1 Shizi Street, Suzhou 215006, China
We study the absorption properties of ultrathin conductive films in the microwave regime, and find a moderate absorption effect which gives rise to maximal absorbance 50% if the sheet (square) resistance of the film meets an impedance matching condition. The maximal absorption exhibits a frequency-independent feature and takes place on an extremely subwavelength scale, the film thickness. As a realistic instance, ∼5 nm thick Au film is predicted to achieve the optimal absorption. In addition, a methodology based on metallic mesh structure is proposed to design the frequency-independent ultrathin absorbers. We perform a design of such absorbers with 50% absorption, which is verified by numerical simulations.
