Study Of Polarization Characteristics Based On Flexible Metamaterials Structures

Metamaterials is a kind of artificial composite materials,with proper design,numerous intriguing phenomena that not exhibited in naturally can be realized.With the development of terahertz technologies and micro structure machining,the researches of terahertz metamaterials has broken through the technical bottleneck.The fabrications of terahertz devices are increasing,like sensors,filters,modulators and so on.These terahertz metamaterials devices have great potential applications in terahertz spectroscopy,imaging and sensors.In this paper,we have designed some terahertz metamaterials structures based on flexible or ultrathin substrate,the spectral responses and polarization characteristics are simulated and measured by using CST Microwave Studio and terahertz time-domain spectroscopy(THz-TDS),respectively.As their special transmission properties,those metamaterials structures could be used as terahertz modulator,filters,and sensors.Ours original works are listed as follow:First,by using U-shaped resonators(URs),we designed two back-to-back U-shaped resonators(TUR)and fourfold U-shaped resonators(FUR).TUR shows strong induction-capacitance resonance for TM mode and dipole resonance for TE mode,and it can be used as a modulator.FUR exhibits polarization-independent characteristics,which can be looked as a polarization-independent dual-channel filter.In addition,due to their flexible properties,our metamaterials could be widely used in terahertz field.Second,we have proposed and demonstrated a tunable plasmon-induced transparency(PIT)effect based on self-asymmetric H-shaped resonators(AHR)meta-atoms.The transmission spectra with different polarization angle have been researched.Transition from PIT mode to dipole mode is theoretically and experimentally demonstrated by simply adjusting the polarization.The AHR can be used as a single/dual-channel filter.In addition,as its PIT effect,the AHR meta-atoms also may be used in slow light.Third,the spoof localized surface plasmons(LSPs)on a textured metallic disk are researched.Compared with normal incidence,the grazing incidence can excite multipolar phenomenon.Also,we proposed a defective metallic disk structure which presenting multipolar effect at the normal incidence.As its higher quality-factor,multipolar effect and enhanced surface field,the defective metallic disk can be used in terahertz sensors.To conclude,some kinds of terahertz metamaterials devices are proposed,which have potential applications in modulators,filters,and sensors,and are meaningful to the development of terahertz regions.