Laser Irradiation on Polymer Materials (Application to Micro-Fabrication and Surface Treatment)
When the polymer material is irradiated by a laser, the surface morphology changes depending on the laser wave-length and the degree of crystallization of the material. For example, infrared laser beam causes the thermal process, and on the contrary ultra-violet laser beam causes the photo-chemical process without thermal damage which is called "ablasion". We are investigating the process by performing the classical and quantum molecular dynamics simulations.

Pit formation caused by infrared (left: wave length 1064nm) and ultra-violet (right: wave length 266nm) laser beams [1].

Surface morphology due to ultra-violet laser irradiation [1] (left: surface after irradiation, right: deposited fragments, upper: without annealing, lower: with annealing).

Classical molecular dynamics simulation of laser irradiation to polymer particle.

Quantum molecular dynamics simulation: Excitation of electron orbit induced by oscillating external electric field.