Transparent material processing with an ultrashort pulse laser

摘要

Methods, devices, and systems for ultrashort pulse laser processing of optically transparent materials are presented, with example applications in scribing, marking, welding, and joining. For example, ultrashort laser pulses create multiple scribe features with one pass of the laser beam across the material, with at least one of the scribe features being formed below the surface of the material. Slightly modifying the ultrashort pulse laser processing conditions produces different types of sub-surface marks. When properly arranged, these marks are clearly visible with correctly aligned illumination through either light scattering or light reflection and nearly invisible without illumination. Transparent material other than glass may be utilized. A method for welding transparent materials uses ultrashort laser pulses to create a bond through localized heating. In some embodiments of transparent material processing, a multifocus beam generator simultaneously forms multiple beam waists spaced depthwise relative to the transparent material, thereby increasing processing speed.

主权项

1. A laser-based method for modification of a material, comprising:
generating a pulsed laser input beam, said pulsed laser input beam comprising a pulse width less than about 100 ps; forming a plurality of focused pulsed beams with different polarizations or different wavelengths from said pulsed laser input beam, said forming comprising:
spatially separating said pulsed laser input beam to form at least two pulsed beams propagating in at least two respective beam paths; andcombining said at least two pulsed beams to form a plurality of collinear beams along a common output propagation path, and focusing said at least two pulsed beams; wherein each focused pulsed beam comprises a beam waist, respective beam waists of said focused pulsed beams being separated and spaced depthwise along the common output propagation path relative to said material, at least one of said beam waists of said focused pulsed beams being within said material and causing material modification within said material that generates at least one sub-surface feature; producing relative motion between said material and said focused pulsed beams; and controlling said forming and said moving in such a way that said plurality of collinear, depthwise separated focused pulsed beams having said different polarizations or different wavelengths are simultaneously delivered to said material during said motion.