Photoexcited broadband blueshift tunable perfect terahertz metamaterial absorber

Design of a concise and dual-band tunable metamaterial absorber

“…3(b) and 3(d) that the electric field is distributed not only on both inner ends of the square ring but also on the adjacent area between the unit cell; the y component of the magnetic field gathers in the middle and both sides of the STO dielectric layer, which indicates that there exists two kinds of different magnetic dipole resonance. Referring to the similar report [28,29] , we deduce that the resonance absorption at high frequency f m2 is caused by a new coupled mode, which combines the fundamental electromagnetic dipole mode with the electromagnetic mode caused by the neighboring square ring. We will discuss this in detail later when analyzing the influence of the geometric parameter.…”

“…3(c). The resonant phenomenon at low frequency f m1 is the fundamental electromagnetic dipole resonance that appeared in some literature [15,21,[27][28][29] . As for the frequency f m2 , it can be seen from Figs.…”

Design of a tunable multiband terahertz waves absorber

“…Recent progress in the passive tuning by the incorporation of naturally occurring materials within or as part of the metamaterial elements has recently been reported. For example, metamaterials have been tuned by loading dielectrics onto their surface and also by integrating semiconductors or carbon nanotubes within the structure to provide electronic or optical control of the resonance frequency [16][17][18][19][20]. Some designers used the methods of using the thermal control to realize the tunability, some were based on a variation of temperature altering the intrinsic carrier density in a semiconductor (InSb) [21,22].…”

“…Some designers used the methods of using the thermal control to realize the tunability, some were based on a variation of temperature altering the intrinsic carrier density in a semiconductor (InSb) [21,22]. Others used the photoexcited carrier by integrating semiconductors into metamaterial designs [19,20,23] and also someone used the property of ferrimagnetic/paramagnetic transition of the M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT ferrites [24]. In addition to the magnetically tunable metamaterial is also a more effective way, some of them used the ferromagnetic precession of ferrite [25] ， and others used the ferromagnetic resonance (FMR) frequency which can be influenced by the dimension of the ferrites [26].…”

“…In these previous works, most of the resonant elements can be represented by an effective inductor-capacitor (LC) resonator, and the resonance frequency is dependent on the effective capacitance C and inductance L. So the method of tunability is introducing another component made from an electro-optic material [31][32][33], liquid crystal [34][35][36], ferrite [37,38], semiconductor [19,20,23] and superconductors [39], liquid metals [40], chemical control [41]to alter L, C or both of them. …”