Design And Study Of A Polarzation Insensitive Superlens

Metasurfaces are functional devices based on subwavelength structures,which can produce changes of optical field phase and amplitude in the planar structures,and are used in many fields such as active tuning,polarization control,wave front shaping and so on.Superlenses based on optical metasurface have great application potential in imaging and integrated photonics.Compared with traditional optical devices,superlenses have the advantages of sub-wavelength scale,small size and low loss,and have advantages in lightweight and miniaturization of devices.The purpose of this work is to design and evaluate the performance of polarization-insensitive hyperlenses.Key contents and innovations include:(1)A "cross" nanocolumn superlens unit structure is designed.At the wavelength of 905nm,the finite-difference time-domain(FDTD)simulation results show that the device structure can cover the full range of 2π phase variation,and the transmittance is greater than 85%and up to 99%with the height of the unit structure at 500nm,550nm and 600nm,and it is insensitive to the polarization of the incident light.Similar to the properties of common "cylindrical" and "hexagonal" nanocolumns,they are also suitable for practical processing.It enriches the unit library of hyperlens unit structures.(2)The performance of the superlens structure at different working wavelengths of the communication band,including phase coverage,focusing effect and transmittance,is studied,and its wide applicability is tested.The three communication wavelengths of 1550nm,1310nm and 850nm were designed respectively,and the results showed that the transmittance reached 83.2%,79.5%and 87.2%respectively,which has good application value in the field of optical communication.