Ultra-high-precision surface structuring by synchronizing a galvo scanner with an ultra-short-pulsed laser system in MOPA arrangement

Abstract

For surface and 3D structuring the ultra short pulsed laser systems are mostly used in combination with galvo scanners. This work reports on the synchronization of the scanner mirror motion with the clock of the laser pulses, which is usually in the range of 100 kHz and higher, by a modification of the electronic scanner control. This synchronization facilitates the placement of the small ablation craters from single pulses with the precision of about 1 µm relative to each other. The precise control of the crater positions offers the possibility to test and optimize new structuring strategies. Results of this optimization process with respect to minimum surface roughness, steepness of wall, accuracy to shape and efficiency will be presented.

Improvements in ultra-high precision surface structuring using synchronized galvo or polygon scanner with a laser system in MOPA arrangement

“…Hence an efficient increase of the material removal rate is only possible by increasing the pulse repetition frequency. Furthermore for a minimized surface roughness the pitch, which means the distance between two consecutive pulses, should be half of the spot radius w 0 4 . In consequence higher removal rates at an optimal surface roughness directly imply increased scanner velocities.…”

Development of Method Enhanced Laser Ablation Efficiency According to Fine Curvature of the Polymer through the Preliminary Preparation Process Using UV Picosecond Laser

“…Laser processing using ultrashort pulse lasers, which began in earnest in the 1990s as a measure to overcome the limitations of UV laser, attracted much attention for the following advantages. First, it enables "cold ablation" which is a type of processing with almost no thermal damage to the periphery of laser irradiated part and almost no secondary damage [25][26][27]. Second, it enables laser processing by the optical phenomenon of nonlinear absorption even with wavelengths at which materials to be processed are not linearly absorbed [28][29][30].…”

Surface Characteristics of Polymers with Different Absorbance after UV Picosecond Pulsed Laser Processing Using Various Repetition Rates

“…The development of ultrashort-pulsed lasers has drawn attention for their two main features. First, they enable non-thermal ablation (cold ablation), a processing technique that yields little thermal or secondary damage around the irradiation area [ 29 , 30 , 31 ]. Second, they can process dielectric materials, such as transparent glass, by nonlinear absorption [ 32 , 33 , 34 ].…”