LAUSR

Abstract Ultrafast lasers have brought revolutionary changes to crystalline materials processing, leading to a wealth of new applications in many areas. In this paper, the authors report a method to modulate crack formation inside a single-crystal sapphire using ultrafast laser zero-order Bessel beams. The number of cracks, transverse crack length, and direction of crack propagation can be modulated by adjusting the pulse duration, single pulse energy, and scanning path, independently. Through the crack control method proposed herein, linear and curvilinear cleaving without debris or taper are demonstrated. The experimental results prove that this method of control is feasible and it is easy to achieve curvilinear cleaving of sapphire.