Influence of processing parameters on the structure size of microchannel processed by femtosecond laser

The processing of an ultra-short pulse laser is widely discussed and used in the field of micro machining, especially for precision processing of the hard and brittle materials. Firstly, the ablation ability would reduce with the defocusing distance increase in theory. However, it was found that the microchannel ablation depth is not sensitive to the defocusing distance in the experiments. The theoretical analysis and simulation calculation were carried out in this paper in order to explain the reason for the relationship between them. Secondly, the size of microchannel structure of the silicon wafer and quartz glass in our experiments were determined obviously by the main processing parameters of femtosecond laser. Furthermore, the influence of laser parameters on the structure size was studied. It was proven that the high quality processed of microchannel depend on the reasonable selection and combination of the parameters by femtosecond laser, which provided an important suggestion to process microchannel precisely.