We report on micromilling cavities into fused silica by a 1030 nm femtosecond laser using 2.17 GHz bursts. The milled show an increased depth per layer for higher number of pulses burst while the ablation efficiency is also increased. maximum optimum fluence achieved in our experiments <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mn>3.05</mml:mn> <mml:mspace width="thickmathspace"/> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msup> <mml:mi...

Thin film ablation with pulsed nanosecond lasers can benefit from the use of beam shaping optics to transform Gaussian profile a circular footprint into Top-Hat rectangular footprint. In general, quality transformed depends strongly on alignment entire laser system. particular, adjustment element is upmost importance. For an appropriate shaper, it generally necessary observe intensity distribution near focal position applied focusing optics. Systems low numerical aperture (NA) commonly be...

We report on the fabrication of an axicon by applying a two-step manufacturing process including 1030 nm femtosecond and 10.6 µm CO2 laser. First, pre-defined geometry is generated high-precision layer-by-layer ablation. In order to meet high surface quality requirements, inevitable stipulated for optical use, thus structured smoothened subsequent laser polishing process. The finalized fulfills as roughness Ra significantly reduced from 0.56 34 nm. For evaluation quality, placed in...

Laser-based fabrication can be an alternative technology to mechanical grinding and polishing processes. However, the performance of these elements in real applications still needs validated. In this paper, we demonstrate that subtractive is able produce high-quality axicons from fused silica, which efficiently used for glass processing. We comprehensively investigate axicons, fabricated by ultrashort pulsed laser ablation with subsequent CO2 polishing, compare their commercially available...

In this contribution, we report on the generation of internal microchannels with basically unlimited channel length inside PMMA bulk material by femtosecond laser. A precisely controllable and stable circular cross section is obtained using a spatial light modulator to compensate writing depth depending spherical aberration. Furthermore, rotatable elliptical input beam adaptive optics ensures fitting shaping direction. study, both, effect ellipticity correction aberration circularity...

We report on a comprehensive study of laser percussion microvia drilling FR-4 printed circuit board material using ultrashort pulse lasers with emission in the green spectral region. Laser durations pico- and femtosecond regime, repetition rates up to 400 kHz fluences 11.5 J/cm2 are applied optimize quality microvias, as being evaluated by generated taper, extension glass fiber protrusions damage inner lying copper layers materialography. The results discussed terms ablation threshold for...

We present a comprehensive experimental study on laser-induced hierarchic nano-micro periodic surface structures brass that influences wetting behavior. Using ultra short laser pulses with wavelength of 1030 nm, large scaled areas completely covered by (LIPSS) are generated these being superimposed ablation trenches and u-ripples. The influence the incident fluence pulse overlap apparent contact angle for coverage distilled water tension 74 mN/m examined its temporal evolution observed over...

We report on the fabrication and evaluation of a sharp tip negative axicon paving way for applications in high-power ultrashort pulsed laser systems. The is manufactured by applying two-step all laser-based process chain consisting ablation CO2 polishing finishing component less than 5 minutes. finalized reveals surface roughness 18 nm, fulfilling optical quality. Two measurement setups, including itself, are used to evaluate formation Bessel beams detail. By focusing lens behind axicon,...

We present a comparative study of laser scribing different thin solid films using nanosecond pulses with wavelengths and beam profiles.In particular, we show the influence used profile for processing 150nm Indium Tin Oxide transparent conductive film multilayer system, consisting metal oxide (TCO) layers deposited on soda lime glass substrate.For 1064nm, 532nm 355nm were Gaussian Top-Hat profile.The homogenous is generated both, refractive diffractive shaper.The results several advantages...

We report on a comparison between simulated and experimental results for the generation of laser-induced periodic surface structures with low spatial frequency dielectrics. Using established efficacy factor theory extended by Drude model, we determine required carrier density LIPSS (LSFL) forecast their periodicity orientation. In subsequent calculative step, fluence ultrashort laser pulses necessary to excite this in due consideration pulse number dependent ablation threshold. The later...

In this contribution we report on the possibilities of dry and lubricated friction modification introduced by different laser surface texturing methods. We compare potential Laser-Induced Periodic Surface Structures Laser Beam Interference Ablation 100Cr6 steel in a linear reciprocating ball-on-disc configuration using tungsten carbide balls with load forces between 50 mN 1000 mN. For friction, find possibility to reduce coefficient observe pronounced direction dependency for surfaces...

The authors report on the rapid fabrication of an axicon array, consisting 37 individual axicons in a hexagonal arrangement, made fused silica by all laser-based manufacturing method within only 23 min. Therefore, two-step process is used, first to ablate substrate layer-by-layer process, generating predefined geometry array with femtosecond laser, and second polish rough optical element applying CO2 laser reach smooth surfaces. Here, roughness reduced from 0.36 μm before 48 nm after...

Abstract We report on the characterization of a hybrid laser scanning system using acousto-optical deflectors in combination with galvanometer scanners for ultra-short pulse material processing. The is characterized by roundness static pulsed ablations metal thin film transparent substrate within field at different scanner deflection angles and focal positions. An ablation more than 90% reached defocusing range 200 $$\upmu \text{m}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">...

We report on the generation of low spatial frequency laser-induced periodic surface structures along straight lines fused silica by spatially scanning laser parallel to its polarization direction. The influence applied fluence and speed is investigated. parameter study shows that appear in a limited regime combined scan with periodicities smaller than wavelength. Most strikingly, we observe perpendicular orientation self-assembled electrical field laser, notably previously unreported result...

We report on the effect of different transversal beam shapes efficiency ablation processes and resulting surface characteristics.A possibility to efficiently apply ultrashort pulsed lasers with high average power is shaping.By using a cooled reflective based liquid crystal spatial light modulator generate spot distributions, it possible spatially allocate available avoid excessive fluences.In our experiments, we determine optimal fluence ablate maximum volume per watt be in range...

Abstract We report on a comprehensive study of laser percussion microvia drilling Ajinomoto build-up film (ABF) material using an ultrashort pulsed in MHz burst mode. After processing, quality is being evaluated by the fabricated diameter and taper scanning microscopy metallography. The influences incubation effect, heat accumulation shielding effects as result pulse to interactions are discussed ablation threshold, penetration depth quality. find that increasing mode processing responsible...

We report on a comprehensive study of laser ablation and micromachining alumina using high-power 1030 nm ultrashort-pulsed laser. By varying power up to 150 W, pulse duration between 900 fs 10 ps, repetition rates 200 kHz 800 kHz), spatial overlap 70% 80% layer-wise rotation the scan direction, efficiency, rate surface roughness are determined discussed with respect an efficient optimized process strategy. As result, combination high longest evaluated ps leads highest efficiency 0.76...

We report on the fabrication of rectangular microchannels with vertical sidewalls in fused silica by laser backside ablation. A 515 nm femtosecond is focused an objective a NA 0.5 through sample glass/air interface, allowing processing from into bulk material. Experimental investigations reveal logarithmically increasing depth channels number scans, while keeping focal position fixed. certain scans has to be applied generate shaped their can controlled fluence 2.64 µm 13.46 and corresponding...

We report on manufacturing of a compact beam homogenizer module including two lens arrays and an aperture. Lens are fabricated by all laser-based technology employing precise femtosecond pulsed laser ablation CO2 polishing step. Each array is processed revealing high contour accuracy roughness 25 nm. The 8x8 designed to have square footprint generate quadratic Top-Hat profile focal length 10 mm realize packaging. Firstly, the tested in experimental setup using commercial holders with their...

Laser turning with ultra-short laser pulses provides the possibility of manufacturing rotationally symmetric geometries, even hard to machine materials as fused silica, down a micrometer scale.In this micro machining approach, beam is oriented perpendicularly rotational axis and tangentially material, whereas target geometry realized by moving constantly rotating specimen according specified under focused spot.Due friction-less ablation it possible realize process in silica without use...