固体浸没透镜的近场光场分析

Analysis of the near-field optical field of solidim mersion lens

采用二维时域有限差分法(2D FDTDmethod)研究了线偏振的高斯光束透过固体浸没透镜(SIL)的近场矢量光场分布特性。分析模拟结果表明,SIL底面的出射光场发生了退极化,产生了与入射光偏振方向垂直的退极化分量;退极化分量的存在使出射总光场的光斑得到一定程度的“加宽”;与入射光偏振方向相同的分量场的光斑均小于总场的光斑,且SIL的折射率越大,两者的差别也越大。

Using two-dimension finite-difference time-domain ( 2D-FDTD) method,the optical fields of solid immersion lens are studied when ill uminated by linear polarized focusing Gaussian beam.The simulated results reveal that the portrait optical field is produced,which broadenes the emitted beam ra dius.The beam of the component field whose polarization is parallel to the incid ent beam is smaller than that of the total optical field and the higher the refr active index is,the larger the contrast is.