Heat transfer analysis of two wavelengths laser microprocessing inside glass

We investigated the relationship between size of melting marks formed inside glass and irradiation time and absorptivity of femtosecond laser beam. For this investigation the absorptivities for static exposure in fs-laser processing (femtosecond laser microprocessing inside glass) was estimated to approximately 4.5 [%]. Also the size of melting marks formed by fs-laser processing was measured with two irradiation times (1/125 [s] and 1/4 [s]). The sizes were much the same. Thus, in this time scale, the size was nearly independent of the irradiation time. Furthermore, luminescence phenomenon that occurred in fs-laser processing was observed. The duration of this luminescence was less than 2/1000 [s]. With the above experimental results, we demonstrated numerical heat transfer analysis during the fs-laser processing. From the experimental and numerical results it thought that the most process in fs-laser processing finishes within 2/1000 [s].