利用高对比度光栅实现光束大角度偏转

Large angle deflection of beam using high contrast grating

为了分析高折射率对比度光栅(HCG)参量和入射波长对光束偏转角的影响,采用严格耦合波法设计了透射光束可偏转非周期三角HCG,并通过时域有限差分法证明了所设计的非周期三角HCG可实现30.3°的透射光束偏转。结果表明,当低折射率介质材料折射率从1增加到1.4时,透射光束偏转角可实现11°的调谐;当入射波长从波长1.5μm增加到1.6μm时,该非周期三角HCG可实现3.527°的透射光束偏转角调谐。这一研究结果可对将来制备高性能光束偏转光栅提供理论指导。

In order to analyze the influence of high contrast grating(HCG)parameters and incident wavelength on beam deflection angle,the rigorous coupled wave method was used to design a deflectable non-periodic triangular HCG,and it is proved that 30.3°beam deflection can be achieved in the designed non-periodic triangular HCG by the finite-difference time-domain(FDTD).At the same time,it is found that when the refractive index of the low refractive index material increases from 1 to 1.4,the deflection angle of the transmission beam can achieve 11°tuning,and when the incident wavelength increases from 1.5μm to 1.6μm,the aperiodic triangular HCG can achieve 3.527°transmission beam deflection angle tuning.The results can provide theoretical guidance for the fabrication of high-performance beam deflection gratings in the future.