METHOD AND APPARATUS FOR LASER-CUTTING OF TRANSPARENT MATERIALS
A method for cutting a transparent brittle material using pulsed laser-radiation is disclosed. A beam of pulsed laser-radiation having an optical-axis is focused in the material by a variable-focus lens or mirror. The focus is translated along the optical-axis while the material is moved with respect to the beam to create an array of defects along a cutting path.
1 . A method for cutting a workpiece along a cutting path using a beam of pulsed laser-radiation from a source thereof, the beam of pulsed laser-radiation having an optical-axis, the beam of pulsed laser-radiation focused to a focus-location on the optical-axis, the method comprising:
translating the focus-location along the optical-axis between first and second opposite surfaces of the workpiece;
moving the workpiece continuously in a plane transverse to the optical-axis, such that the optical-axis follows the cutting path; and
wherein translating the focus-location within the moving workpiece creates a two-dimensional array of defects within the workpiece.
2 . The method as recited in claim 1 , wherein the defects do not overlap.
3 . The method as recited in claim 1 , wherein the array of defects has a saw-tooth pattern.
4 . The method as recited in claim 1 , wherein the array of defects has a sinusoidal pattern.
5 . The method as recited in claim 1 , wherein translating the focus-location along the optical-axis is accomplished using a variable-focus lens.
6 . The method as recited in claim 1 , wherein translating the focus-location along the optical-axis is accomplished using a variable-focus mirror.
7 . The method as recited in claim 1 , further comprising the step of separating the workpiece along the cutting line after the array of defects is formed.
8 . The method as recited in claim 1 , wherein the workpiece is of a material transparent to the beam of pulsed laser-radiation.
9 . The method as recited in claim 1 , wherein the workpiece is glass.
10 . The method as recited in claim 1 , wherein the pulsed laser-radiation has a pulse-duration less than about 20 picoseconds.
11 . A method for cutting a workpiece along a cutting path using a beam of pulsed laser-radiation from a source thereof, the workpiece having first and second opposite surfaces, the beam of pulsed laser-radiation having an optical-axis, the method comprising:
moving the workpiece continuously in a plane transverse to the optical-axis, such that the optical-axis follows the cutting path;
focusing the beam of pulsed laser-radiation to a focus-location on the optical-axis and within the workpiece, the focus-location adjacent to the first surface for delivery of a first laser-radiation pulse;
translating the focus-location along the optical-axis towards the second surface during delivery of successive laser-radiation pulses, until a last laser-radiation pulse is delivered when the focus-location is adjacent to the second-surface;
refocusing the beam of pulsed laser-radiation, the focus-location within the workpiece and adjacent to the first surface for delivery of another first laser-radiation pulse; and
repeating the translating and refocusing steps while the optical-axis moves along the cutting path to create a two-dimensional array of defects within the workpiece.
12 . The method as recited in claim 11 , wherein the second surface of the workpiece is between the source of pulsed laser-radiation and the first surface of the workpiece.
13 . The method as recited in claim 11 , wherein the defects do not overlap.
14 . The method as recited in claim 11 , wherein translating the focus-location along the optical-axis and refocusing the beam of pulsed-laser radiation is accomplished using a variable-focus lens.
15 . The method as recited in claim 11 , wherein translating the focus-location along the optical-axis and refocusing the beam of pulsed-laser radiation is accomplished using a variable-focus mirror.
16 . The method as recited in claim 11 , further comprising the step of separating the workpiece along the cutting line after the array of defects is formed.
17 . The method as recited in claim 11 , wherein the workpiece is of a material transparent to the beam of pulsed laser-radiation.
18 . The method as recited in claim 11 , wherein the workpiece is glass.
19 . The method as recited in claim 11 , wherein the pulsed laser-radiation has a pulse-duration less than about 20 picoseconds.