Near-field distribution of broadband antireflective nanostructure arrays

Broadband antireflection (AR) nanostructure arrays patterned directly into a bulk substrate, behaving as the expected performance of high laser induced damage threshold (LIDT), is proposed for the application of laser-transmitting optical elements. These regular periodic arrays known as “moth-eye” structure exhibit particularly noteworthy AR property over a wide spectrum and over a large field of view in addition to overcome efficiently the disadvantages of multilayer AR thin-film. Furthermore, the near-field distribution in nanostructure arrays with respect to the period, the groove depth and incident angle, respectively, was numerically simulated using a rigorous Fourier modal method (FMM). It is interesting that the maximum value of the normalized electric field intensity is obviously distributed inside the air layer upon the nanostructure for the periodicity of 100 nm, which has significant potential to reach to ultra high LIDT for the application of short-pulse high-power laser system. Besides, the variation of the near-field distribution inside the nanostructure arrays exhibits critically dependent on the period of surface structure, but the effect caused by the discrepancy in groove depth and incident angle is unimportant.