Methods for ultrashort pulse laser processing of optically transparent materials. A method for scribing transparent materials uses ultrashort laser pulses to create multiple scribe features with a single pass of the laser beam across the material, with at least one of the scribe features being formed below the surface of the material. This enables clean breaking of transparent materials at a higher speed than conventional techniques. Slightly modifying the ultrashort pulse laser processing conditions produces sub-surface marks. When properly arranged, these marks are clearly visible with side-illumination and not clearly visible without side-illumination. In addition, a method for welding transparent materials uses ultrashort laser pulses to create a bond through localized heating. The ultrashort pulse duration causes nonlinear absorption of the laser radiation, and the high repetition rate of the laser causes pulse-to-pulse accumulation of heat within the materials. The laser is focused near the interface of the materials, generating a high energy fluence at the region to be welded. This minimizes damage to the rest of the material and enables fine weld lines.

Transparent material processing with an ultrashort pulse laser

A method is provided for the internal processing of a transparent substrate in preparation for a cleaving step. The substrate is irradiated with a focused laser beam that is comprised of pulses having an energy and pulse duration selected to produce a filament within the substrate. The substrate is translated relative to the laser beam to irradiate the substrate and produce an additional filament at one or more additional locations. The resulting filaments form an array defining an internally scribed path for cleaving said substrate. Laser beam parameters may be varied to adjust the filament length and position, and to optionally introduce V-channels or grooves, rendering bevels to the laser-cleaved edges. Preferably, the laser pulses are delivered in a burst train for lowering the energy threshold for filament formation, increasing the filament length, thermally annealing of the filament modification zone to minimize collateral damage, improving process reproducibility, and increasing the processing speed compared with the use of low repetition rate lasers.

Method of material processing by laser filamentation

Femtosecond laser induced phenomena in transparent solid materials: Fundamentals and applications

With the advancement of glass technology in recent times, glass has become one of the most important engineering materials in architectural, medical, automotive, flat panel display, and electronics applications. Desired shape and size of the glass can only be achieved through accurate and precise cutting technique. Laser technology has an advantage over traditional cutting processes for glass due to good quality, surface finish, and high speed of operation. This paper provides a review of all the laser glass cutting techniques discovered in recent work and forms a comparison framework, in particular, their limitations and their current status which would facilitate prospective research and future development.

Laser glass cutting techniques—A review

Forming holes in a material includes focusing a pulsed laser beam into a laser beam focal line oriented along the beam propagation direction and directed into the material, the laser beam focal line generating an induced absorption within the material, the induced absorption producing a defect line along the laser beam focal line within the material, and translating the material and the laser beam relative to each other, thereby forming a plurality of defect lines in the material, and etching the material in an acid solution to produce holes greater than 1 micron in diameter by enlarging the defect lines in the material. A glass article includes a stack of glass substrates with formed holes of 1-100 micron diameter extending through the stack.

Method for rapid laser drilling of holes in glass and products made therefrom

We propose an idea of fast cutting a display glass plate where the sample is pre-processed micromachining single shot rear-surface and internal void arrays aligned on working plane prior to glass cleaving. Single shot void morphology is investigated varying input pulse energy, focusing depth, and scanning speed. A femtosecond laser with pulse duration of 172 fs, central wavelength of 780 nm, and repetition rate of 1 kHz is used to fabricate voids.

Display glass cutting by femtosecond laser induced single shot periodic void array

PROBLEM TO BE SOLVED: To provide a long tool life for a diamond tip mounted on a diamond cutting tool. SOLUTION: After completing shape forming of the diamond tip mounted on the distal end of the diamond cutting tool such as a diamond cutting tool, an ultrashort pulsed laser beam is cast to the surfaces of the diamond tip in contact with a workpiece so that a finely rugged surface having a periodic structure of 5 nm to 3,000 nm is formed. Since frictional resistance between the tip and the contact surface is reduced, the resistance during the cutting is lowered, realizing the longer tool life of the diamond tip. COPYRIGHT: (C)2009,JPO&INPIT

Diamond cutting tool using laser and its manufacturing method

Femtosecond laser ablation using the combination of 260 nm pulses and 780 nm pulses is explored for the high speed and high quality selected removal of insulating layers.

Dual Wavelength Femtosecond Laser Materials Processing

We solved the stability, life-time and cost problems of femtosecond lasers and opened the door to their huge commercial market in near future. Femtosecond lasers will be used in the semiconductor and LCD manufacturing factory.

Masanao Kamata

Papers

Display glass cutting by femtosecond laser induced single shot periodic void array

Diamond cutting tool using laser and its manufacturing method

Dual Wavelength Femtosecond Laser Materials Processing

Advanced femtosecond lasers in Manufacturing