High-Q And Polarization-independent Terahertz Metamaterial Absorber

As the foundation of terahertz functional applications,metamaterial absorbers have been intensively studied.However,THz metamaterial functional devices commonly suffer from a quality factor(Q-factors)lower than 10 owing to ohmic and radiation losses.Recently,the most popular method to improve quality factor is split ring resonator.However,the use of split ring resonator can break the structure's symmetry and make devices to be polarization-related,which cause great difficulties in practice.Consequently,ensuring a good tradeoff between high Qfactor and polarization independency is key challenge for designing practicable terahertz metamaterial devices.Our work aimed to balance this tradeoff and designed a high-Q and polarization-independent terahertz metamaterial absorber by CST computing method.And we have studied theory analysis,design of structure and performances' exploration.Research of basic theory for terahertz metamaterial absorber.We analyzed the transmission of terahertz waves in absorbers and concluded necessary conditions to achieve perfect absorption.we deeply studied the theory of impedance match,metal resonation,skin-depth in metals and computing principle in the sequence from top to the bottom.It can provide good theory foundation for design of expected absorber.Structure design and theoretical analyzation of high-Q and polarizationindependent terahertz metamaterial absorber.We confirmed rational parameters of silicon layer,Al resonator and polypropylene layer to design expected absorber.Meanwhile,we verified perfect absorption theory combining above-mentioned theory analyzation and simulation by CST software.Performance research and application's exploration of designed absorber.In order to study the resonating absorption performance of designed device,we solved the resonating frequency and simulated the relationship between frequency and many parameters,including top layer's refractive index,metal's variety,the thickness of dielectric layer and incident direction,so as to find the key influence factors and optimize designed device.Finally,we expanded the structure by changing resonator's structure in order to satisfy different application demands and made a solid foundation for the further exploration of the designed high-Q and polarization-independent terahertz metamaterial absorber.