Dynamically tunable broadband absorber with a single ultra-thin layer of graphene in the terahertz regime

A dual ultra-broadband switchable high-performance terahertz absorber based on hybrid graphene and vanadium dioxide

“…Subsequent incident waves are normal-incidence TE-polarized waves if not otherwise specified. 41 When the graphene Fermi energy is 0.0 eV and the VO 2 conductivity is 200 000 S m −1 , a high-frequency broadband absorption of 4.9–10 THz is achieved with an absorption rate of over 90% (blue solid line). When VO 2 is in the insulated state, the conductivity is 200 S m −1 , and the Fermi energy of graphene is set at 0.7 eV.…”

Review of Broadband Metamaterial Absorbers: From Principles, Design Strategies, and Tunable Properties to Functional Applications

“…Gratefully, the emergence and development of active materials have perfectly solved the issues of MAs' fixed and unchanged absorption features. Because these active materials themselves are subject to changes in temperature, [93][94][95][96] bias voltage, [103][104][105] pump light, [110][111][112] and other parameters that lead to changes in their own (dielectric) properties.…”

“…Thus the ideas of tunable (or reconfigurable) BMAs have been given and suggested to overcome this dilemma. [90][91][92] By integrating some active components (or materials) into the structural engineering designs of BMAs, the absorption behavior of BMAs could be dynamically controlled or adjusted via applying external stimuli, such as temperature/thermal, [93][94][95][96] electric field, [97][98][99] magnetic field, [100][101][102] bias voltage, [103][104][105] applied stress/force, [106][107][108][109] pump beam, [110][111][112] etc.…”

A tunable broadband terahertz MoS2 absorber using series–parallel hybrid network design

“…In the current single-layered structures, frequency-selective surfaces usually adopt regular shapes, such as circular, spiral, cross line, and square ribbon, to achieve a Special Display and Imaging Technology Innovation Center of Anhui Province, broadband characteristics. [21][22][23][24][25][26] However, the relative bandwidth of these patterns is limited because their equivalent circuits are simple series RLC circuits or parallel circuits. 19,24,27 The insufficient bandwidth of single-layered structures, as well as the large size and the complexity of the multilayered structures, limits the practical application of tunable 2D material absorbers.…”