超短パルスレーザー干渉加工法における第二高調波の応用

Abstract

Interference pattern of two different wavelengths, forming a four-sided pyramid consisting of eight beams, is discussed. By using two wavelengths with relation of λ1=2λ2, interference pattern can be formed in numerical simulation. Phase shift and amplitude variation of interfering beams are useful to obtain a variety of interference patterns. On the other hand, ultra-violet femtosecond laser was applied to interfering femtosecond laser processing. MHA (Metallic-Hole Array) structure was fabricated in 100 nm and 200 nm thick gold thin films successfully by multiple shots. The period was minified to 0.76 µm.