Nano polishing of a rough quartz surface: Numerical calculation of surface evolution

• A 3D model of nano-local photochemical etching for polishing a rough quartz surface when this surface is illuminated from the quartz side at the critical angle of total internal reflection has been developed. • Unpolarized light is not suitable for the implementation of the quartz photochemical polishing technology using total internal reflection, since the direction of the vector of the electric component of electromagnetic radiation significantly affects the distribution of the maxima and minima of the electric field over the surface irregularities. It does not allow to get effective nanolocal etching of irregularities in all directions. • The use of two sources of linearly polarized laser radiation illuminating the surface in orthogonal planes at the critical angle of total internal reflection provides in this case the required level of roughness.ab. A numerical 3D model of nano-local photochemical etching for polishing a rough quartz surface has been developed. This surface is illuminated from the quartz side at the critical angle of total internal reflection. The light source is a laser coherent monochromatic radiation with linear polarization, and the electric field strength vector lies in the plane of light incidence. The model uses a numerical solution of the Helmholtz equation using the finite elements method. The proposed model allows to describe the evolution of etching of a rough surface and obtain a subnano-meter level of surface roughness. The results of calculation show that the use of two independent sources of linearly polarized laser radiation provides the required level of surface roughness and increases the efficiency of the model compared to direct illumination.