scholarly journals Preparation of metal nanoparticles by femtosecond laser ablation

2018 ◽  
Vol 17 (1) ◽  
pp. 38-47
Author(s):  
Tibor Teplicky ◽  
Dusan Chorvat ◽  
Miroslav Michalka ◽  
Alzbeta Marcek Chorvatova
Keyword(s):  
Femtosecond Laser ◽  
Femtosecond Laser Ablation ◽  
Laser Pulses ◽  
Spectroscopic Properties ◽  
Femtosecond Laser Pulses ◽  
Environmental Research ◽  
Spherical Particles ◽  
Order Of Magnitude ◽  
Spectrally Resolved ◽  
Ultrashort Laser

Abstract Nanoparticles (NPs) proved to have numerous applications in various fields, including biomedicine and environmental sciences. In this work, we designed and created an apparatus for fabrication of metal NPs directly in liquids initiated by femtosecond laser pulses. The laser parameters leading to ~10 μJ/pulse energy and 0.1 GW peak power resulted in predominantly spherical particles with the sizes varying from <10 nm to ~100 nm in diameter. NPs generated from Cobalt and Zinc targets were smaller in order of magnitude compared to that of Nickel. The fabricated NPs were characterized by scanning electron microscopy, while spectroscopic properties were investigated by absorption spectroscopy and spectrally resolved fluorescence imaging. We also tested the possible interaction of the created NPs with living algae for their potential use for environmental research. Employing such ultrashort laser opens route to provide on-demand production of NP's in-situ at even factory environment.

scholarly journals A study of substrate temperature distribution during ultrashort laser ablation of bulk copper

2007 ◽  
Vol 25 (1) ◽  
pp. 155-159 ◽  
Author(s):  
Y.C. LAM ◽  
D.V. TRAN ◽  
H.Y. ZHENG
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Thermal Power ◽  
Femtosecond Laser Ablation ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Laser Materials ◽  
Laser Ablation Process ◽  
Copper Specimen ◽  
Ultrashort Laser

With the aid of an infrared thermograph technique, we directly observed the temperature variation across a bulk copper specimen as it was being ablated by multiple femtosecond laser pulses. Combining the experimental results with simulations, we quantified the deposited thermal power into the copper specimen during the femtosecond laser ablation process. A substantial amount of thermal power (more than 50%) was deposited in the copper specimen, implying that thermal effect can be significant in femtosecond laser materials processing in spite of its ultrashort pulse duration.

Picosecond Single-Photon and Femtosecond Two-Photon Pulsed Laser Stimulation for IC Characterization and Failure Analysis

2009 ◽  
Author(s):  
V. Pouget ◽  
E. Faraud ◽  
K. Shao ◽  
S. Jonathas ◽  
D. Horain ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Single Photon ◽  
Pulsed Laser ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Laser Stimulation ◽  
Two Photon ◽  
Resolution Improvement ◽  
Ultrashort Laser

Abstract This paper presents the use of pulsed laser stimulation with picosecond and femtosecond laser pulses. We first discuss the resolution improvement that can be expected when using ultrashort laser pulses. Two case studies are then presented to illustrate the possibilities of the pulsed laser photoelectric stimulation in picosecond single-photon and femtosecond two-photon modes.

Femtosecond Laser Ablation of Zr55Al10Ni5Cu30 Bulk Metallic Glass

2007 ◽  
Vol 539-543 ◽  
pp. 1951-1954 ◽  
Author(s):  
Tomokazu Sano ◽  
Kengo Takahashi ◽  
Akio Hirose ◽  
Kojiro F. Kobayashi
Keyword(s):  
Laser Ablation ◽  
Metallic Glass ◽  
Femtosecond Laser ◽  
Bulk Metallic Glass ◽  
Pulse Energy ◽  
Femtosecond Laser Ablation ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Ablation Depth ◽  
Polished Surface

Dependence of the femtosecond laser ablation depth on the laser pulse energy was investigated for Zr55Al10Ni5Cu30 bulk metallic glass. Investigation of the femtosecond laser ablation of bulk metallic glasses has not been reported. Femtosecond laser pulses (wavelength of 800 nm, pulse width of 100 fs, pulse energies of 2 – 900 μJ) were focused and irradiated on the polished surface of metals in air. The ablation depth of the metallic glass is deeper than that of its crystallized metal at a pulse energy in the strong ablation region. We suggest that the energy loss at grain boundaries of hot electrons which is accelerated by the laser electric field influence the ablation depth in the strong ablation region.

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.

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 Structure-Mediated Excitation of Air Plasma and Silicon Plasma Expansion in Femtosecond Laser Pulses Ablation

Research ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Qingsong Wang ◽  
Lan Jiang ◽  
Jingya Sun ◽  
Changji Pan ◽  
Weina Han ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Femtosecond Laser Ablation ◽  
Longitudinal Direction ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Pulse Number ◽  
Air Plasma ◽  
Laser Material ◽  
Anisotropic Expansion ◽  
Multiple Pulses

Femtosecond laser-induced surface structures upon multiple pulses irradiation are strongly correlated with the pulse number, which in turn significantly affects successive laser-material interactions. By recording the dynamics of femtosecond laser ablation of silicon using time-resolved shadowgraphy, here we present direct visualization of the excitation of air plasma induced by the reflected laser during the second pulse irradiation. The interaction of the air plasma and silicon plasma is found to enhance the shockwave expansion induced by silicon ablation in the longitudinal direction, showing anisotropic expansion dynamics in different directions. We further demonstrate the vanishing of air plasma as the pulse number increases because of the generation of a rough surface without light focusing ability. In the scenario, the interaction of air plasma and silicon plasma disappears; the expansion of the silicon plasma and shockwave restores its original characteristic that is dominated by the laser-material coupling. The results show that the excitation of air plasma and the laser-material coupling involved in laser-induced plasma and shockwave expansion are structure mediated and dependent on the pulse number, which is of fundamental importance for deep insight into the nature of laser-material interactions during multiple pulses ablation.

scholarly journals Fabricating waveguide Bragg gratings (WBGs) in bulk materials using ultrashort laser pulses

Nanophotonics ◽  
2017 ◽  
Vol 6 (5) ◽  
pp. 743-763 ◽  
Author(s):  
Martin Ams ◽  
Peter Dekker ◽  
Simon Gross ◽  
Michael J. Withford
Keyword(s):  
Femtosecond Laser ◽  
Ion Beam ◽  
Laser Pulses ◽  
Bragg Gratings ◽  
Femtosecond Laser Pulses ◽  
Ultrafast Laser ◽  
Ultrashort Laser Pulses ◽  
Clean Room ◽  
Bulk Materials ◽  
Ultrashort Laser

AbstractOptical waveguide Bragg gratings (WBGs) can be created in transparent materials using femtosecond laser pulses. The technique is conducted without the need for lithography, ion-beam fabrication methods, or clean room facilities. This paper reviews the field of ultrafast laser-inscribed WBGs since its inception, with a particular focus on fabrication techniques, WBG characteristics, WBG types, and WBG applications.

Localized Electron Evolution Induced by Femtosecond Laser Pulses in Water

2001 ◽  
Author(s):  
C. H. Fan ◽  
J. Sun ◽  
J. P. Longtin
Keyword(s):  
Femtosecond Laser ◽  
Electron Density ◽  
Inhomogeneous Plasma ◽  
Optical Breakdown ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Rate Equations ◽  
Focal Region ◽  
Ultrashort Laser

Abstract Optical breakdown by ultrashort laser pulses in dielectrics presents an efficient method to deposit laser energy into materials that otherwise exhibit minimal absorption at low laser intensities. During optical breakdown, a high density of free electrons is formed in the material, which dominates energy absorption, and, in turn, the material removal rate during ultrafast laser-material processing. Classical models assume spatially uniform electron population and constant laser intensity in the focal region, which results in a time-dependent expressions only, i.e., the rate equations, to predict electron evolution induced by nanosecond and picosecond pulses. For femtosecond pulses, however, the small spatial extent of the pulse requires that the pulse propagation be considered, which results in inhomogeneous plasma and localized electron formation during optical breakdown. In this work, a femtosecond breakdown model is combined with the classical rate equations to determine both time- and position-dependent electron density during femtosecond optical breakdown in water. The model exhibits good agreement when compared with experimental results. For other transparent or moderately absorbing dielectric media, the model also shows promise for determining the time- and position-dependent electron evolution induced by ultrashort laser pulses. Another interesting result is that the maximum electron density formed during femtosecond-laser-induced optical breakdown can exceed the conventional limit imposed by the plasma frequency.

scholarly journals Femtosecond Laser Pulses: Generation, Measurement and Propagation

2021 ◽  
Author(s):  
Mounir Khelladi
Keyword(s):  
Laser Pulse ◽  
Femtosecond Laser ◽  
Ultrashort Laser Pulse ◽  
Short Pulse ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Light Pulses ◽  
Large Bandwidth ◽  
Temporal Shape ◽  
Ultrashort Laser

In this contribution some basic properties of femtosecond laser pulse are summarized. In sections 2.1–2.5 the generation of femtosecond laser pulses via mode locking is described in simple physical terms. In section 2.6 we deal with measurement of ultrashort laser pulses. The characterization of ultrashort pulses with respect to amplitude and phase is therefore based on optical correlation techniques that make of the short pulse itself. In section 3 we start with the linear properties of ultrashort light pulses. However, due to the large bandwidth, the linear dispersion is responsible for dramatic effects. To describe and manage such dispersion effects a mathematical description of an ultrashort laser pulse is given first before we continue with methods how to change the temporal shape via the frequency domain. The chapter ends with a paragraph of the wavelet representation of an ultrashort laser pulse.

ENERGY TRANSMITTANCE AND SPATIAL PHASE IMPROVEMENT OF INTENSE ULTRASHORT LASER PULSES IN GAS-FILLED HOLLOW FIBER USING PRESSURE GRADIENT METHOD

2004 ◽  
Vol 13 (02) ◽  
pp. 291-299 ◽  
Author(s):  
MUHAMMAD NURHUDA ◽  
HERU BUDIONO ◽  
AKIRA SUDA ◽  
KATSUMI MIDORIKAWA
Keyword(s):  
Femtosecond Laser ◽  
Pressure Gradient ◽  
Hollow Fiber ◽  
Gradient Method ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Input Energy ◽  
Spatial Phase ◽  
Ultrashort Laser

A pressure gradient method for spectral broadening of intense-femtosecond laser pulses in gas-filled hollow fiber is proposed. The simulations using input energy of 6 mJ and pulse duration of 40 fs have shown that using the same value of ∫ p(x)dx, the energy transmittance can be enhanced by a factor of 25% compared to that of using constant gas pressure while the global spatial phase is also improved.

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