The effects of laser irradiation upon thin-film samples were investigated by means of micro-Raman spectroscopy. It was found that the laser heating affected the thin films to different degrees at various power levels. At a laser power density of below 1mW/μm2, laser irradiation caused only thermal expansion within the focussed area. When the power density was increased to about 1.7mW/μm2, O out-diffusion occurred.

Raman Study of Laser Irradiation Effects on YBa2Cu3O7 Thin Films. X.B.Wang, Z.X.Shen, S.Y.Xu, C.K.Ong, M.H.Kuok, S.H.Tang: Superconductor Science and Technology, 2000, 13[7], 1017-22