相关论文: Spallative ablation of dielectrics by X-ray laser
The mechanism of ablation of solids by intense femtosecond laser pulses is described in an explicit analytical form. It is shown that at high intensities when the ionization of the target material is complete before the end of the pulse,…
The microscopic mechanism of metal ablation induced by ultrashort laser pulse irradiation is investigated. A two-temperature model scheme combined with molecular dynamics (TTM-MD) is developed to incorporate electronic entropy effects into…
Laser-induced water ablation triggers various physical effects, including atom ionization, optical breakdown of the liquid, phase explosion, cavitation, and shockwave propagation. These effects can be further amplified in heavy water by…
Ultrashort-pulse laser ablation of metals near damage threshold is governed by homogeneous spallation, in which tensile unloading releases a nanometre-thin liquid film whose optical signatures are temporally evolving concentric Newton rings…
Irradiating materials with ultra-short laser pulses generates unwanted shock waves which distort the interesting physics. Advanced boundary conditions are presented to erase even very strong shock waves. Depending on the wave length, laser…
We report an experimental and numerical investigation of the fragmentation mechanisms of micrometer-sized metal droplet irradiated by ultrashort laser pulses. The results of the experiment show that the fast one-side heating of such a…
We report the physical reasons of a curious decrease in the crater depth observed for long delays in experiments with femtosecond double pulses. Detailed hydrodynamic modeling demonstrates that the ablation mechanism is dumped when the…
Lasers are becoming a more and more important tool in cutting and shaping materials. Improving precision and effectivity is an ongoing demand in science and industry. One possibility are double pulses. Here we study laser ablation of…
An intense, short laser pulse incident on a transparent dielectric can excite electrons from valence to the conduction band. As these electrons undergo scattering, both from phonons and ions, they emit bremsstrahlung radiation. Here we…
It is observed that the interaction of an intense ultra-short laser pulse with an overdense gas jet results in the pulse collapse and the deposition of a significant part of energy in a small and well localized volume in the rising part of…
Selective thin-film removal is needed in many microfabrication processes such as 3-D patterning of optoelectronic devices and localized repairing of integrated circuits. Various wet or dry etching methods are available, but laser machining…
Electron and phonon transient temperatures are analyzed in the case of nondegenerate semiconductors. An analytical solution is obtained for rectangular laser pulse absorption. It is shown that thermal diffusion is the main energy relaxation…
Laser fragmentation of suspended microparticles is an upcoming alternative to laser ablation in liquid (LAL) that allows to streamline the the delivery process and optimize the irradiation conditions for best efficiency. Yet, the structural…
The effects of ultra-short laser pulses on reactive Ti/Al nano-layered thin film were investigated. The thin film composed of alternated titanium and aluminium nano-layers, was deposited by ion-sputtering. Single pulse irradiation was…
The fragmentation of a liquid metal droplet induced by a nanosecond laser pulse has been studied well. However, the fragmentation mechanism may be different, when a subpicosecond laser pulse is applied. To discover the details of the…
A number of works point to the presence of narrow emission features at unusual energies in the X-ray spectra of active galactic nuclei (AGN) or to potentially low iron abundances as possible evidence for the spallation of iron. With the…
An investigation of ultrashort pulsed laser induced surface modification due to conditions that result in a superheated melted liquid layer and material evaporation are considered. To describe the surface modification occurring after…
Femtosecond laser ablation is a process that bears both fundamental physics interest and has wide industrial applications. For decades, the lack of probes on the relevant time and length scales has prevented access to the highly…
Electron-electron thermalization and electron-phonon relaxation processes in laser-excited solids are often assumed to occur on different timescales. This is true for the majority of the conduction band electrons in a metal. However,…
We present one-dimensional numerical simulations describing the behavior of solid matter exposed to subpicosecond near infrared pulsed laser radiation. We point out to the role of strong isochoric heating as a mechanism for producing highly…