Controlling the sidewall verticality of a CVD diamond in Gaussian laser grooving

Abstract

For the specific energy distribution of Gaussian laser, the obtained grooves always fall short in the sidewall verticality. To overcome this problem, the improvement of sidewall inclination in laser grooving of a CVD diamond is undertaken by the surface tilting motion control, where the insufficient material removal at the groove sidewall is relieved. Combined with finite element modelling, the influence of laser energy density, scanning speed, scanning times and scanning pitch on the inclination of sidewall are firstly analyzed, which shows that laser energy density is the main factor that dominates the sidewall inclination. The finite element simulation model (FEM) is established to achieve the contour evolution of the machining area under different tilted angles, where the generation mechanism of ‘V’ shape or ‘W’ shape at the bottom of the groove is analyzed. Finally, the inclination degree of the groove sidewall can be effectively controlled by optimizing the relative incident angle under the selected laser energy density.

Single-Step Fabrication of Highly Tunable Blazed Gratings Using Triangular-Shaped Femtosecond Laser Pulses

“…In recent years, ultrafast direct laser writing (DLW) has become a popular and cost-effective method for facilitating the fabrication process [ 23 , 24 ]. Several strategies have explored the inclusion of this technique, for example, 3D laser-assisted lithography, where electron beam lithography is substituted in the exposure of the photoresist [ 25 , 26 ], or oblique engraving, which can be achieved by significantly tilting the substrate with respect to the incident laser beam [ 27 , 28 ]. However, these approaches are not ideal because they either require a multi-step manufacturing process or involve operating in non-orthogonal positioning, which could make their industrial implementation challenging.…”