近红外波长超透镜的设计与仿真

超透镜是超表面在成像领域中具有较大应用潜力的平面光学器件,能够精确调控光的相位、振幅、偏振等信息、兼容互补金属氧化物半导体(Complementary Metal Oxide Semiconductor,CMOS)制造工艺,在器件轻量化和批量化制造等方面具有很大的发展前景。针对近红外成像镜头的轻量化需求,使用时域有限差分(finite difference time domain,FDTD)软件设计仿真了工作波长为800nm的硅基偏振不敏感超透镜,镜头厚度小于0.5mm,数值孔径为0.41时聚集效率为75。针对FDTD软件仿真时间较长、硬件要求较高、平面波边缘消散等问题,提出了三维和远场计算相结合的仿真方法；利用波印廷矢量和电场强度积分两种方法分别对超透镜聚集效率进行了计算。对比实验表明:三维和远程计算相结合的方法仿真时间降低了70,计算机内存需求降低了50。

Near infrared wavelength metalens design and simulation

Metalens is a planar optical device with great application potential in the imaging field which can precisely control the phase,amplitude,polarization,and other information of light. It is compatible with the manufacturing process of complementary metal oxide semiconductor(CMOS). Moreover,it has great development prospects in the lightweight and mass manufacturing of devices. To meet the lightweight requirements for near infrared imaging lens,a silicon based polarization insensitive metalens with a working wavelength of 800 nm is designed and simulated by using finite difference time domain(FDTD) software. Metalens thickness is less than 0.5mm. The focusing efficiency is 75% when the numerical aperture(NA) is 0.41. Aiming at the problems of time consuming of FDTD software simulation,high requirements for hardware,plane wave edge dissipation and so on,a simulation method combining three dimensional and far field calculation is proposed. Two methods of Poynting vector and electric field intensity integration are used to calculate the focusing efficiency of metalens respectively. The comparison experiment shows that the simulation time is reduced by 70% and the requirement of computer memory is reduced by 50%.