Topdown femtosecond laser-interference technique for the generation of new nanostructures

Precise and periodic structure can be formed on and inside materials by interfering femtosecond laser processing. In this method, laser ablation or modification is induced according to the interference pattern. In our technique, this method is applied to thin film processing, and nano-sized structures such as nanobumps, nanomeshs, and nanobelts. Nanobump array structure can be formed by periodic thermal processes induced by a single shot of interfering laser. Field emission from a nanobump array was demonstrated. By processing at relatively higher fluence, a grating, a circular or a ellipsoidal hole array structure can be generated according to the number of beams. By exfoliating the structures, nanobelt or nanomesh structure can be generated. This is a top-down technique for the generation of new nanomaterials.