Application of the two-temperature model for a numerical study of multiple laser pulses interactions with thin metal films

Majchrzak, Ewa; Dziatkiewicz, J.

doi:10.17512/jamcm.2012.2.07

Cited by 5 publications

(10 citation statements)

References 6 publications

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“…A basic theoretical model, the two-temperature (2-T) model, is used to calculate the thermal transport in solid. The 2-T model is given as two coupled diffusion equations, representing the temperature evolutions of the lattice and electrons, respectively [19,20,21]. The temperature evolution of the silicon lattice shows the process of phase changes over time, and the solidification time will be used for explaining the formation of the patterns left on the surface.…”

Section: Theoretical Methodsmentioning

confidence: 99%

“…The temperature evolution of the silicon lattice shows the process of phase changes over time, and the solidification time will be used for explaining the formation of the patterns left on the surface. A laser pulse function including the laser profiles and its effects on the material will be presented as the driving source of the electron diffusion equation [19,20,21].…”

Section: Theoretical Methodsmentioning

confidence: 99%

“…Most previous works assume a uniform distribution of laser intensive along the transverse direction and neglect the thermal transport along the transverse or radial direction in a solid, a 1D system [19,20,21]. Whereas, most of the laser beams are in a Gaussian profile, and the instantaneous energy distribution along the radial direction in a solid should also be close to a Gaussian.…”

Section: Theoretical Methodsmentioning

confidence: 99%

“…Thus, we write the laser pulse function in cylindrical coordinates as shown in the right side diagram in Figure 1. Its time dependent part along the optical axis x is as given [20,21]:Q(x,t)=βπ 1−Rtp δI0 Exp[−xδ−β (t−2tp)2tp2] where β is 4ln2, R is the reflectivity of the solid surface with respect to the laser wavelength, t p is the pulse duration of the laser, δ is the penetration depth of the material, and I 0 is the fluence of the laser. Optical axis x and time t are the basic variables of this 1D laser pulse function.…”

Section: Theoretical Methodsmentioning

confidence: 99%

“…Other than the vaporized or escaped species, the patterns left on sample surface attract our interests because of their regularity in nanoscale and convenience for applications in making devices. Explanations using laser profiles, thermal properties of materials, solidification of capillary waves, photon diffractions, and plasmonic effect have been previously introduced to understand the formation of these patterns [13,16,19,20,21,22,23]. Straight ripples with uniform periodicity have been generated on different material surfaces by using a linearly polarized laser beam, and diffraction mechanism was successfully implemented to explain the formation of these structures [8,24,25].…”

Section: Introductionmentioning

confidence: 99%

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Femtosecond Laser-Induced Thermal Transport in Silicon with Liquid Cooling Bath

et al. 2019

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Nanostructured regular patterns on silicon surface are made by using femtosecond laser irradiations. This is a novel method that can modify the surface morphology of any large material in an easy, fast, and low-cost way. We irradiate a solid surface with a 400-nm double frequency beam from an 800-nm femtosecond laser, while the solid surface is submerged in a liquid or exposed in air. From the study of multiple-pulses and single-pulse irradiations on silicon, we find the morphologies of nanospikes and capillary waves to follow the same distribution and periodicity. Thermal transport near the solid surface plays an important role in the formation of patterns; a simulation was done to fully understand the mechanism of the pattern formation in single pulse irradiation. The theoretical models include a femtosecond laser pulse function, a two-temperature model (2-T model), and an estimation of interface thermal coupling. The evolution of lattice temperature over time will be calculated first without liquid cooling and then with liquid cooling, which has not been well considered in previous theoretical papers. The lifetime of the capillary wave is found to be longer than the solidification time of the molten silicon only when water cooling is introduced. This allows the capillary wave to be frozen and leaves interesting concentric rings on the silicon surface. The regular nanospikes generated on the silicon surface result from the overlapping capillary waves.

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Section: Theoretical Methodsmentioning

confidence: 99%

Section: Theoretical Methodsmentioning

confidence: 99%

Section: Theoretical Methodsmentioning

confidence: 99%

Section: Theoretical Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Femtosecond Laser-Induced Thermal Transport in Silicon with Liquid Cooling Bath

et al. 2019

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Optical-acoustic excitation of broadband terahertz antiferromagnetic spin waves

zhang

et al. 2022

New J. Phys.

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We propose an optical-acoustic means to excite broadband terahertz antiferromagnetic (AFM) spin wave in a metal/insulator/antiferromagnet heterostructure. The AFM spin wave is excited by an ultrafast strain wave triggered by a femtosecond pulsed laser based on photoacoustic conversion. This spin wave comprises an AFM exchange spin wave and a magnetoelastic spin wave. Their dispersion curves are overlapped in a wide frequency range by manipulating the Dzyaloshinskii-Moriya interaction (DMI), which is accompanied by lifting the degeneration of the spin-wave modes with opposite chirality. This optical-acoustic excitation of spin waves exploits the laser-induced ultrafast strain waves and avoids the thermal effect from the laser. It paves a way to develop novel AFM devices that can apply for ultrafast information processing and communication.

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