Aug 13, 2015 Off Comments in Laser Cutting by

Laser processing of optically transparent or semi-transparent, brittle materials is finding wide use in various manufacturing sectors. For example, in consumer electronic devices such as smartphones, e-readers, and tablets, cover glass needs to be cut precisely in various shapes.

Processing of transparent brittle materials using ultrafast lasers provides advantages in comparison with long-pulse lasers. When an ultrafast laser is focused inside glass, only the localized region in the neighborhood of the focal volume absorbs laser energy by nonlinear optical absorption. Therefore, the processing volume is strongly defined locally, while the remainder of the target is unaffected. While ablative femtosecond processing provides the quality that industrial users demand, processing speed needs to be improved to achieve widespread economical industrial use. In this article, we describe a newly developed non-ablative femtosecond process, ClearShape, using the Spirit industrial femtosecond laser. The ClearShape process allows machining of curvilinear and internal closed-shape features in transparent, brittle materials such as chemically strengthened glass, unstrengthened glass, and sapphire with high quality and speed.

High cutting speed with unprecedented quality

Ultrafast lasers, with pulse duration in the femtosecond time scale, have proven their potential in many material processing applications. The unique advantages of ultrafast lasers, including high ablation efficiency and high accuracy of ablated structures on metal and dielectric targets, have been demonstrated in several studies [1-4]. Although the processing quality achieved meets industrial demands, processing speed needs to be improved to satisfy an economical industrial use [5, 6]. For example, our studies have shown that by using a commercially available industrial femtosecond laser system, the maximum cutting speed with an ablative process of 0.2mm/s is feasible for 0.5mm-thick chemically strengthened glass, which is not applicable in an industrial process [7]. Recently, Spectra-Physics developed a non-ablative femtosecond, patent-pending laser process called ClearShape to machine transparent and brittle material with cutting speed >1 m/s and very high quality.

Read more: Cleveland Ohio Laser Cutting : Femtosecond laser processing of brittle materials