金膜上亚波长周期性孔阵的模拟与研制

Simulation and Development of Subwavelength Periodic Hole Array on Au Film

分析了980 nm波长的光在透过制作在金膜上的亚波长周期性孔阵时的透射增强现象。通过建立中心带缺陷孔的三角晶格的孔阵模型,并采用三维时域有限差分方法对该模型的透射情况进行模拟分析。结果表明通过优化孔阵周期参数可以对特定波长的光实现一定程度的选择透过性。当孔阵周期为450 nm,中心缺陷孔径为400 nm,孔阵中单个孔孔径为150 nm时,980 nm波长光透过该孔阵时具有明显的透射增强效应,并且距孔阵表面3 μm的远场光斑尺寸被局限在亚波长尺度(880 nm)。研究了使用聚焦离子束在金膜上制备孔阵的工艺,成功研制了与设计尺寸一致的孔阵。这种孔阵可以集成在980 nm垂直腔面发射激光器上,用于改善器件的远场光学特性。

The enhanced transmission phenomenon of 980 nm wavelength light through sub-wavelength periodic hole arrays on Au film was analyzed. A triangular lattice hole arrays model with centric defect mode hole was established. By using three-dimensional finite difference time domain（3D-FDTD）method, the property of transmission has been numerically analyzed. The results show that the transmission with given wavelength can be enhanced by optimizing the periodic parameters of hole arrays. When the period of hole arrays, diameter of centric hole and diameter of air holes are 450 nm, 400 nm, 150 nm respectively, the transmission field can be confined to a spot with sub-wavelength width （880 nm） in 3 μm far-field from hole array surface. The fabrication technology of hole array on Au film by using focused ion beam （FIB） was studied, and the expected hole array was developed. This hole arrays can be integrated onto a 980 nm wavelength VCSEL lasers to optimize the far-field characteristic of the device.