Gorilla Glass Cutting Using Femtosecond Laser Pulse Filaments

Abstract

Due to high durability, scratch resistance, and impact resistance, Gorilla glasses are a popular choice for protective screens of smartphones, tablets, and laptops. Precise cutting of Gorilla glasses is very important to maintain the overall aesthetics and user experience, which is very challenging. We demonstrated for the first time the cutting of Gorilla glass by means of femtosecond laser filamentation technique. To achieve laser filamentation, a femtosecond laser beam was focused and irradiated in different depths of the sample Gorilla glasses. The filament length varied with the change in the focus position of the laser beam. The effective numerical aperture of the objective lens rises due to the presence of dielectric material (i.e., the Gorilla glass itself) before the focus position of the femtosecond laser beam inside the glass samples. As a consequence, the focal distance of the incident laser beam was prolonged and focused in a very tiny spot with extremely high energy density. Consequently, filaments (i.e., high aspect ratio micro-voids) were evident inside the Gorilla glass samples. The filament length is controllable by changing the irradiation parameters of the laser beam, including magnification and numerical aperture of the lens, laser energy, and thickness of the Gorilla glass before the target focal point. The filament-engraved Gorilla glass samples go through mechanical cleaving process with 400 MPa pressure on both sides of the laser scanning line for smooth cutting of Gorilla glass. The proposed glass cutting technique show promises for commercial application.