# Gorilla Glass Cutting Using Femtosecond Laser Pulse Filaments
## 1 Introduction  
Since its development in 2007 by Corning, Gorilla glass has attracted researchers and leading manufacturers in the consumer electronics industry. Because of its excellent strength, scratch resistance, and durability, Gorilla glass gained widespread adoption in the display industry and is considered an ideal choice for touchscreens. Precise cutting of Gorilla glass is important because the aesthetics of touchscreen devices are highly dependent on the quality of glass cutting, smooth curves, and clean edges contributing to the overall appearance and mechanical quality of the device. Like other glass materials, it is very challenging to cut Gorilla glasses precisely; smooth curves and clean edges are especially difficult to achieve [1, 2]. Most widely used techniques of glass cutting are based on handheld tools like glass cutters and straightedges for scoring and breaking the glass sample along the desired lines. Another widely used manual glass cutting technology is based on a handheld diamond cutter [3]. However, manual glass cutting technologies require proper selection of glass cutters and holding technology for appropriate cutting of glass substrates. Furthermore, the quality of the glass edges after manual cut is too poor to be considered for display devices [2, 3]. As a result, various automatic glass cutting techniques come to the forefront of research: diamond cutter-based automatic technology [4], hot air jet technology [5], water jet technology [6], milling technology [7, 8],plasma technology [9], ultrasonic technology [10], wire saw technology [11], and laser technology [12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22; 23; 24; 25; 26]. Diamond cutter-based automatic technology suffers from poor processing speed, fragility of the diamond tip, unsmooth edge quality, and health hazards caused by the generation of dust and debris. On the contrary, hot air jet technology experiences poor edge quality, edge cracking, low precision, heat stress, and air pollution due to the formation of fumes and particulate matter. Water jet technology, on the other hand, has several limitations: poor edge quality, possibility of cracking, poor processing speed, formation of taper in the cut, health hazard caused by water pollution, and expense. In contrast, milling technology suffers from waste generation, slow processing speed, poor edge quality, programming complexity, and risk of chipping or breakage. Plasma technology experiences poor edge quality, formation of a heat affected zone, and limited thickness. On the contrary, ultrasonic technology has the limitations of thickness and processing speed. Wire saw technology suffers from poor precision and accuracy, poor edge quality, cracking or chipping, waste generation, slow processing speed, and high installation cost. Because of high precision, high processing speed, excellent edge quality, minimal material waste, and low surface contamination, laser-assisted technologies can be considered a promising tool for cutting a large variety of glass materials. Initially, CO\({}_{2}\) lasers were considered for cutting glass substrates [12; 13; 14]. Although CO\({}_{2}\) lasers are one of the most widely used technologies for glass cutting, CO\({}_{2}\) laser-based glass cutting technology experiences several limitations. CO\({}_{2}\) lasers can lead to cracking or chipping along the edges of the cut. Sometimes, post processing or grinding may be required to improve edge quality. Furthermore, CO\({}_{2}\) laser beams are mostly absorbed by most of the glass materials, which can lead to slow cutting speed and the need for high power to achieve the desired results. Pulsed lasers also showed promise in good quality glass cutting [15; 16; 17; 18; 19; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29]. Several research groups utilized nanosecond lasers for engraving lines in glasses or cutting various kinds of thin glass substrates [15; 16; 17; 18].