scholarly journals Micromachining of Transparent Biocompatible Polymers Applied in Medicine Using Bursts of Femtosecond Laser Pulses

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1093
Author(s):  
Evaldas Kažukauskas ◽  
Simas Butkus ◽  
Piotr Tokarski ◽  
Vytautas Jukna ◽  
Martynas Barkauskas ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Femtosecond Laser ◽  
Contact Lenses ◽  
Laser Pulses ◽  
Laser Micromachining ◽  
Femtosecond Laser Pulses ◽  
Intraocular Lenses ◽  
Great Promise ◽  
Biocompatible Polymers ◽  
Mechanical Methods

Biocompatible polymers are used for many different purposes (catheters, artificial heart components, dentistry products, etc.). An important field for biocompatible polymers is the production of vision implants known as intraocular lenses or custom-shape contact lenses. Typically, curved surfaces are manufactured by mechanical means such as milling, turning or lathe cutting. The 2.5 D objects/surfaces can also be manufactured by means of laser micromachining; however, due to the nature of light–matter interaction, it is difficult to produce a surface finish with surface roughness values lower than ~1 µm Ra. Therefore, laser micromachining alone can’t produce the final parts with optical-grade quality. Laser machined surfaces may be polished via mechanical methods; however, the process may take up to several days, which makes the production of implants economically challenging. The aim of this study is the investigation of the polishing capabilities of rough (~1 µm Ra) hydrophilic acrylic surfaces using bursts of femtosecond laser pulses. By changing different laser parameters, it was possible to find a regime where the surface roughness can be minimized to 18 nm Ra, while the polishing of the entire part takes a matter of seconds. The produced surface demonstrates a transparent appearance and the process shows great promise towards commercial fabrication of low surface roughness custom-shape optics.

Characterization of Electrical Contacts on Silicon (100) after Ablation and Sulfur Doping by Femtosecond Laser Pulses

2013 ◽  
Vol 205-206 ◽  
pp. 358-363 ◽  
Author(s):  
Philipp Saring ◽  
Anna Lena Baumann ◽  
Stefan Kontermann ◽  
Wolfgang Schade ◽  
Michael Seibt
Keyword(s):  
Surface Roughness ◽  
Femtosecond Laser ◽  
Laser Pulses ◽  
Sample Surface ◽  
Femtosecond Laser Pulses ◽  
Electrical Contacts ◽  
Single Shot ◽  
Excess Charge ◽  
Silicon Sample ◽  
Etching Depth

This paper investigates the influence of different number of laser pulses on contact behavior and conductivity of the surface layer of femtosecond laser microstructured, sulfur-doped silicon. Single shot laser processed silicon (Pink Silicon) is characterized by low surface roughness, whereas five shot laser processed silicon (Grey Silicon) has an elevated sulfur content with a surface roughness low enough to maintain good contacting. To laterally confine the laser induced pn-junction part of the Grey Silicon sample surface is etched off. The etching depth is confirmed to be sufficient to completely remove the active n-type sulfur layer. While Pink Silicon shows little or no lateral conductivity within the laser processed layer, Grey Silicon offers acceptable conductivity, just as expected by the fact of having incorporated a higher sulfur dopant content. Recombination dominates the irradiated regions of Pink Silicon and suppresses excess charge carrier collection. Grey Silicon, while showing sufficient lateral conductivity, still shows regions of lower conductivity, most likely dominated by the laser irradiation-induced formation of dislocations. According to our results, the optimum laser pulse number for electrical and structural properties is expected to be in the range between one and five laser pulses.

scholarly journals Editorial for the Special Issue on Femtosecond Laser Micromachining for Photonics Applications

Micromachines ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 994
Author(s):  
Andrea Crespi ◽  
Giacomo Corrielli
Keyword(s):  
Femtosecond Laser ◽  
Laser Pulses ◽  
Laser Micromachining ◽  
Femtosecond Laser Pulses ◽  
Special Issue ◽  
Femtosecond Laser Micromachining

Femtosecond laser pulses have proven, in the recent years, their formidable potential as a micromachining tool applicable to a variety of materials [...]

Machining of Biocompatible Polymers with Shaped Femtosecond Laser Pulses

2013 ◽  
Author(s):  
C. Schuster ◽  
C. Merschjann ◽  
N. Rothe ◽  
S. Fiedler ◽  
R. Irsig ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Biocompatible Polymers

Surface Roughness and Crystallinity of Silicon Solar Cells Irradiated by Ultraviolet Femtosecond Laser Pulses

2020 ◽  
Vol 140 (8) ◽  
pp. 401-406
Author(s):  
Fumitaka Nigo ◽  
Masaki Hashida ◽  
Masahiro Tsukamoto ◽  
Shuji Sakabe ◽  
Mitsuhiro Kusaba
Keyword(s):  
Surface Roughness ◽  
Solar Cells ◽  
Femtosecond Laser ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Silicon Solar Cells

Rapid Prototyping of Glass Microfluidic Devices using Femtosecond Laser Pulses

2004 ◽  
Vol 820 ◽  
Author(s):  
Myung-Il Park ◽  
Jun Rye Choi ◽  
Mira Park ◽  
Dae Sik Choi ◽  
Sae Chae Jeoung ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Rapid Prototyping ◽  
Laser Fluence ◽  
Femtosecond Laser Ablation ◽  
Microfluidic Devices ◽  
Soda Lime ◽  
Laser Pulses ◽  
Laser Micromachining ◽  
Femtosecond Laser Pulses ◽  
Mems Devices

AbstractLaser micromachining technology with 150 femtosecond pulses is developed to fabricate glass microfluidic devices. A short theoretical analysis of femtosecond laser ablation is reported to characterize the femtosecond laser micromachining. The ablated crater diameter is measured as a function of the number of laser pulses as well as laser fluence. Two different ablation regimes are observed and the transition between the regimes is dependent on both the laser fluence and the number of laser shots. Based on the ablation phenomena described, microfluidic devices are fabricated with commercially available soda lime glasses (76 mm × 26 mm × 1 mm, Knittel Glaser, Germany). In addition to a microchannel for microfluidics, the capillary as well as optical fiber for detecting is integrated on the same substrate. The substrate is successively packaged with a lid slide glass by a thermal direct bonding. The presented developments are suitable for fast turn-around design cycle and inexpensive procedure, which provide rapid prototyping of MEMS devices.

scholarly journals Laser-induced transient magnons in Sr3Ir2O7 throughout the Brillouin zone

2021 ◽  
Vol 118 (22) ◽  
pp. e2103696118
Author(s):  
Daniel G. Mazzone ◽  
Derek Meyers ◽  
Yue Cao ◽  
James G. Vale ◽  
Cameron D. Dashwood ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Brillouin Zone ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Magnetic Interactions ◽  
Great Promise ◽  
X Ray ◽  
Magnetic Correlations ◽  
X Ray Scattering ◽  
Physical Phenomena

Although ultrafast manipulation of magnetism holds great promise for new physical phenomena and applications, targeting specific states is held back by our limited understanding of how magnetic correlations evolve on ultrafast timescales. Using ultrafast resonant inelastic X-ray scattering we demonstrate that femtosecond laser pulses can excite transient magnons at large wavevectors in gapped antiferromagnets and that they persist for several picoseconds, which is opposite to what is observed in nearly gapless magnets. Our work suggests that materials with isotropic magnetic interactions are preferred to achieve rapid manipulation of magnetism.

Femtosecond Laser Micromachining of High Quality Groove on Sapphire Surface

2012 ◽  
Vol 217-219 ◽  
pp. 2213-2216
Author(s):  
Li Tao Qi ◽  
Jin Ping Hu
Keyword(s):  
Femtosecond Laser ◽  
Scanning Speed ◽  
Laser Pulses ◽  
Laser Micromachining ◽  
Femtosecond Laser Pulses ◽  
High Quality ◽  
Experimental Conditions ◽  
Sapphire Surface ◽  
Femtosecond Laser Micromachining ◽  
High Scanning Speed

In this paper, high quality grooves were fabricated by femtosecond laser pulse on sapphire surface. Grooves were fabricated under different experimental conditions. The lateral and vertical machining precision was evaluated by scanning electron microscopy and profilometer. High quality grooves could be obtained at the condition of low pulse energy, high scanning-speed and increasing the number of laser scans. The relationship between the width and depth of the groove and the key parameters of femtosecond laser micromachining system was studied. Several samples of the high quality grooves were obtained by femtosecond laser pulses. High quality grooves have a potential application of the fabrication of sapphire-based devices.

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