Fano resonance based ultra high-contrast electromagnetic switch

Abstract

We experimentally achieve highly asymmetrical enhanced-Q Fano resonances in metallic electromagnetic structures fabricated on conductive planes. We show that the complete destructive interference mechanism of the dark and bright resonant modes generated by a pair of electromagnetically coupled open-ended conductive arms can lead to the asymmetric resonance characterized by a near-unity transparency window followed by a deep scattering band. With the incorporation of a variable capacitor between the coupled metallic strips, the dynamic tunability of the resonant modes is achieved, which can be exploited in high isolation switches and modulators in the GHz spectrum. The switching contrast of over 50 dB achieved through Fano resonance is much higher considering its compact size (i.e., the transmission path is much smaller than the wavelength λ/30). The dispersion based tunable Fano switch offers several advantages over conventional microelectromechanical system and CMOS based switches.

Slow Wave Applications of Electromagnetically Induced Transparency in Microstrip Resonator

“…The interference effects leading to sharp spectral features of EIT resonance are ultra-sensitive to surrounding materials. This makes it beneficial for sensing 7 – 9 and optical switching 10 , 11 applications. It means that the molecular binding events of a biological or chemical analyte within the near field region can be efficiently detected 12 .…”

“…Even though high Q-factors with a theoretical limit of 15000 were achieved, the resonator-array substrate rendered a bulky structure hard to integrate within the current trend of low profile electronics. Recently, we demonstrated microstrip based resonator for non-invasive sensing 18 and an ultrahigh contrast Fano switching applications 10 .…”

A perfect Fresnel acoustic reflector implemented by a Fano-resonant metascreen

“…58 Owing to the fact that this is a general phenomenon, several applications in different fields have been put forward, e.g., switching, sensing, or in nonlinear optics. 36,[59][60][61][62][63] The dynamic control of amplitude and phase characteristics of optical waves was shown in graphene-based Fano resonances. 59 In the framework of acoustics, several studies have been conducted to demonstrate acoustically induced transparency (AIT) and acoustic Fano resonance using optics-inspired techniques, such as the acoustic mode coupling with significantly different Q-factors.…”

Linearly Tunable Fano Resonance Modes in a Plasmonic Nanostructure with a Waveguide Loaded with Two Rectangular Cavities Coupled by a Circular Cavity

“…Typically, plasmonic structures exhibiting conventional quasi-Lorentzian resonance are always characterized by symmetric and wide lineshape in their transmission spectra [10,11,12], which would limit their applications. To solve this problem, considerable attention has been paid to Fano resonances [13,14,15]. Fano resonance modes in SPP structures exhibit sharp and asymmetric spectral lineshape [16,17].…”