Investigations on the quality improvement of laser processing for LN

For achieving high-quality cutting of LiNbO3, we conducted precision cutting experiments by using the femto-second laser, including Bessel beam filament cutting and nonlinear filament cutting. Basing on the advantages of both methods, we have designed a novel cutting scheme, which effectively combines the two methods. First, we use an axicon to conduct breakthrough modification to form an optical channel; then the objective lens is used to focus the laser to scan the modification area and remove the materials in the modification area. It can finally realize the fine cutting of the LN wafer with small edge chipping and low section roughness. The surface and cross-section morphology of the specimens were examined by stereomicroscope, optical microscopy (OM) and scanning electron microscopy (SEM), and the roughness of the cutting section was measured by the white light interferometer.