非周期高透射亚波长会聚光栅的研究

摘要

Sub-wavelength grating as a novel optical device can achieve beam deflection, power split, convergence, polarization splitting and other functions.Coupling for spatial light and beam type requirements for micro laser output light.Sub-wavelength grating with transmission beam convergence effect is proposed.By designing the structure of the sub-wavelength grating, the wavefront phase of the sub-wavelength grating is controlled so that the sub-wavelength grating has a high transmittance to achieve the convergent effect of the transmitted beam.The finite element analysis (FEM) was used to simulate the numerical value of the designed one-dimensional non-periodic sub-wavelength convergence grating.The simulation results show that the non-periodic grating designed by the finite element method has convergent effect on the divergent beam.The simulated transmission grating with a focal length of10μm is converged.The actual focal length fx obtained by the simulation is 7.715μm and the transmittance is 81.8％.It is expected to have important applications in the field of optical communication device integration and space optical coupling.%亚波长光栅作为一种新颖的光学器件可以实现光束的偏转、功分、会聚、偏振分束等功能.针对空间光的耦合以及微型激光器输出光的束型需求,本文提出了一种具有透射光束会聚效果的一维亚波长光栅,通过对亚波长光栅的结构设计,控制亚波长光栅的波前相位使得亚波长光栅具有高的透射率,以实现透射光束的会聚效果.利用有限元分析法(FEM)对设计的一维非周期亚波长会聚光栅数值进行仿真,结果表明:仿真焦距在10μm处的光束会聚的透射光栅,仿真得到的实际焦距fx为7.715μm,透射率为81.8％.因此,利用有限元法设计的非周期光栅对发散光束具有优异的会聚效果,有望在光通信器件的集成以及空间光耦合领域得到重要应用.