Design And Research Of Near And Mid Infrared Metamaterial Absorber Based On Surface Plasmon Polariton

The research on perfect absorption of electromagnetic waves has been a hot field of concern in recent years.The design of metamaterial absorbers based on surface plasmons is also an important path to achieve perfect absorption.Surface plasmons convert the energy of incident electromagnetic waves into electromagnetic waves propagating along the interface of the medium,thereby achieving binding and absorption of electromagnetic waves.As an artificial material,metamaterials have achieved properties that ordinary natural materials cannot possess in many aspects,such as negative refractive index.Such properties have made them widely studied and applied in many aspects.At the same time,metamaterial absorbers based on surface plasmons generally have a subwavelength structure,and they also have excellent scalability on the plane.Therefore,they have good flexibility in the design of absorber structures.In this article,we will design three different types of absorbers,namely,ultra-wideband absorbers,ultra-narrowband absorbers,and chiral absorbers.The specific content is as follows:1.A four trapezoidal and four layer hollow sealed ultra wideband absorber was designed,which achieved all results with an absorption rate greater than 80%within 780 nm to 5500 nm,with an average absorption rate of 87%.At the same time,the central symmetric structural design also achieved insensitivity to the incidence angle and polarization angle.In the exploration of whether there is a sealed hollow rectangular body,we adjusted the parameters,This enables the structure to achieve over 90%high absorption in the waveband range of 2000 nm to 3000 nm,thereby achieving the tunability of the structure.2.A single layer MIM ultra narrow band absorber has been designed,which can achieve an absorption rate of 88.11%at 792.93 nm.Although its absorption rate is relatively low,the full width at half peak is only 3.7 nm,which is smaller than the value of most narrow band absorbers,and its Q value is 214.3.In addition to the above two values,the sensitivity of this device is 796 μ The FOM value of m/RIU is 215.3,which is higher than the performance of the same type of absorber device.In addition,we also found that by adjusting the thickness of the upper cylinder accordingly,the absorption of the device itself can be raised to about 99%,achieving tunable device performance.3.A chiral metamaterial absorber based on MIM was designed.Through adjusting its main parameters,we achieved a CD value of 0.7997 at 4502 nm,and achieved an absorption rate of over 0.75 at 3953 nm,reaching a level of 0.7662.