解説
フォトニックナノジェットの微細表面創製への応用
キーワード:
nano structure,
laser micro machining,
photonic nanojet,
intensity distribution control,
FDTD simulation
2018 年 63 巻 10 号 p. 684-689
詳細
2018 年 63 巻 10 号 p. 684-689
Photonic nanojet (PNJ) is a high intensity light beam generated from a dielectric microsphere illuminated by a laser light. The beam diameter of a PNJ is several hundred nanometers, which is smaller than that of a focused laser beam with a high numerical aperture. A PNJ can propagate longer than 1µm while maintaining a smaller beam diameter than 1µm and a high intensity with little divergence. PNJ has different characteristics from the conventional focused laser beam. These properties of PNJ enable three-dimensional laser micro machining. By controlling the position and the intensity distribution of a PNJ, the processed feature size can be controlled in nanometer scale. Machined holes with the diameter of sub-micrometer scale can be obtain even when the PNJ was defocused by 0.5µm. Control of the intensity distribution of PNJ by incident wavelength enables high resolution control of the hole diameter in nanometer scale. PNJ is suitable for three-dimensional laser micro machining in nanometer scale.
