scholarly journals Derivation of effective penetration depth of femtosecond laser pulses in metal from ablation rate dependence on laser fluence, incidence angle, and polarization

2015 ◽  
Vol 106 (1) ◽  
pp. 013101 ◽  
Author(s):  
Yasuhiro Miyasaka ◽  
Masaki Hashida ◽  
Takaya Nishii ◽  
Shunsuke Inoue ◽  
Shuji Sakabe
Keyword(s):  
Femtosecond Laser ◽  
Penetration Depth ◽  
Laser Fluence ◽  
Incidence Angle ◽  
Laser Pulses ◽  
Ablation Rate ◽  
Femtosecond Laser Pulses ◽  
Rate Dependence ◽  
Effective Penetration

Ablation of Si and Ge Using UV Femtosecond Laser Pulses

1995 ◽  
Vol 397 ◽  
Author(s):  
G. Herbst ◽  
M. Steiner ◽  
G. Marowsky ◽  
E. Matthias
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Material Removal ◽  
Laser Pulses ◽  
Ablation Rate ◽  
Femtosecond Laser Pulses ◽  
Bond Breaking ◽  
Intensity Enhancement ◽  
Silicon And Germanium

ABSTRACTLaser ablation of silicon and germanium was carried out in moderate vacuum with l00fs to 400fs pulses at 248nm and intensities up to 3x1013 W/cm2. Evidence for non-thermal material removal was found. Imaged multishot ablation patterns display the intensity dependent self-structuring effect, forming well-known columnar structures. It is shown that continued irradiation of these structures eventually results in comparatively clean ablation. An increase of ablation rate with depth was observed. The reason is an intensity enhancement inside the pits by reflective focussing to a level where bond-breaking takes place. Furthermore, it was noticed that ablation contours can be significantly improved by electrically grounding the target.

Terahertz radiation from a shallow incidence-angle InAs emitter in a magnetic field irradiated with femtosecond laser pulses

2001 ◽  
Vol 40 (9) ◽  
pp. 1369 ◽  
Author(s):  
Shingo Ono ◽  
Takeyo Tsukamoto ◽  
Eiji Kawahata ◽  
Takayuki Yano ◽  
Hideyuki Ohtake ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Femtosecond Laser ◽  
Terahertz Radiation ◽  
Incidence Angle ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses

scholarly journals Femtosecond laser ablation of brass: A study of surface morphology and ablation rate

2012 ◽  
Vol 30 (3) ◽  
pp. 473-479 ◽  
Author(s):  
Mohamed E. Shaheen ◽  
Brian J. Fryer
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Surface Morphology ◽  
Fine Particles ◽  
Femtosecond Laser Ablation ◽  
Laser Pulses ◽  
Ambient Air ◽  
Ablation Rate ◽  
Femtosecond Laser Pulses ◽  
Nanosecond Laser

AbstractThe interaction of near infrared femtosecond laser pulses with a Cu based alloy (brass) in ambient air at atmospheric pressure and under different laser conditions was investigated. The effects of laser fluence and number of pulses on surface morphology and ablation rate were studied using scanning electron microscopy (SEM) and optical microscopy. Ablation rates were found to rapidly increase from 83 to 604 nm/pulse in the fluence range 1.14–12.21 J/cm2. At fluence >12.21 J/cm2, ablation rates increased slowly to a maximum (607 nm/pulse at 19.14 J/cm2), and then decreased at fluence higher than 20.47 J/cm2 to 564 nm/pulse at 24.89 J/cm2. Large amounts of ablated material in a form of agglomerated fine particles were observed around the ablation craters as the number of laser pulses and fluence increased. The study of surface morphology shows reduced thermal effects with femtosecond laser ablation in comparison to nanosecond laser ablation at low fluence.

scholarly journals Ultrafast dynamical process of Ge irradiated by the femtosecond laser pulses

2016 ◽  
Vol 4 ◽  
Author(s):  
Fangjian Zhang ◽  
Shuchang Li ◽  
Anmin Chen ◽  
Yuanfei Jiang ◽  
Suyu Li ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Pulse Duration ◽  
Laser Fluence ◽  
Carrier Density ◽  
Laser Intensity ◽  
Great Influence ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Lattice Temperature ◽  
Dynamical Process

The ultrafast dynamic process in semiconductor Ge irradiated by the femtosecond laser pulses is numerically simulated on the basis of van Driel system. It is found that with the increase of depth, the carrier density and lattice temperature decrease, while the carrier temperature first increases and then drops. The laser fluence has a great influence on the ultrafast dynamical process in Ge. As the laser fluence remains a constant value, though the overall evolution of the carrier density and lattice temperature is almost independent of pulse duration and laser intensity, increasing the laser intensity will be more effective than increasing the pulse duration in the generation of carriers. Irradiating the Ge sample by the femtosecond double pulses, the ultrafast dynamical process of semiconductor can be affected by the temporal interval between the double pulses.

scholarly journals Laser Fluence Dependence of the Electrical Properties of MoO2 Formed by High Repetition Femtosecond Laser Pulses

2018 ◽  
Vol 215 (19) ◽  
pp. 1800226 ◽  
Author(s):  
Santiago Camacho-Lopez ◽  
Israel O. Perez-Lopez ◽  
Miroslava Cano-Lara ◽  
Alejandro Esparza-Garcia ◽  
M. Carmen Maya-Sanchez ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Femtosecond Laser ◽  
Laser Fluence ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
High Repetition ◽  
Fluence Dependence

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.

Inorganic-organic Hybrid Materials for Real 3-D Sub-νm Lithography

2003 ◽  
Vol 780 ◽  
Author(s):  
R. Houbertz ◽  
J. Schulz ◽  
L. Fröhlich ◽  
G. Domann ◽  
M. Popall ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Sol Gel ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Hybrid Polymer ◽  
Organic Hybrid ◽  
Two Photon ◽  
Applied Technology ◽  
Scale Structures ◽  
Sol Gel Synthesis

AbstractReal 3-D sub-νm lithography was performed with two-photon polymerization (2PP) using inorganic-organic hybrid polymer (ORMOCER®) resins. The hybrid polymers were synthesized by hydrolysis/polycondensation reactions (modified sol-gel synthesis) which allows one to tailor their material properties towards the respective applications, i.e., dielectrics, optics or passivation. Due to their photosensitive organic functionalities, ORMOCER®s can be patterned by conventional photo-lithography as well as by femtosecond laser pulses at 780 nm. This results in polymerized (solid) structures where the non-polymerized parts can be removed by conventional developers.ORMOCER® structures as small as 200 nm or even below were generated by 2PP of the resins using femtosecond laser pulses. It is demonstrated that ORMOCER®s have the potential to be used in components or devices built up by nm-scale structures such as, e.g., photonic crystals. Aspects of the materials in conjunction to the applied technology are discussed.

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