Improved Two-Temperature Model and Its Application in Ultrashort Laser Heating of Metal Films
نویسندگان
چکیده
The two-temperature model has been widely used to predict the electron and phonon temperature distributions in ultrashort laser processing of metals. However, estimations of some important thermal and optical properties in the existing two-temperature model are limited to low laser fluences in which the electron temperatures are much lower than the Fermi temperature. This paper extends the existing two-temperature model to high electron temperatures by using full-run quantum treatments to calculate the significantly varying properties, including the electron heat capacity, electron relaxation time, electron conductivity, reflectivity, and absorption coefficient. The proposed model predicts the damage thresholds more accurately than the existing model for gold films when compared with published experimental results. DOI: 10.1115/1.2035113
منابع مشابه
Influence of Interface Thermal Resistance on Relaxation Dynamics of Metal-Dielectric Nanocomposite Materials under Ultrafast Pulse Laser Excitation
Nanocomposite materials, including noble metal nanoparticles embedded in a dielectric host medium, are interesting because of their optical properties linked to surface plasmon resonance phenomena. For studding of nonlinear optical properties and/or energy transfer process, these materials may be excited by ultrashort pulse laser with a temporal width varying from some femtoseconds to some hund...
متن کاملContribution of Ballistic Electron Transport to Energy Transfer During Electron-Phonon Nonequilibrium in Thin Metal Films
With the ever decreasing characteristic lengths of nanomaterials, nonequilibrium electron-phonon scattering can be affected by additional scattering processes at the interface of two materials. Electron-interface scattering would lead to another path of energy flow for the high-energy electrons other than electron-phonon coupling in a single material. Traditionally, electron-phonon coupling in ...
متن کاملNonlocal thermoelastic semi-infinite medium with variable thermal conductivity due to a laser short-pulse
In this article, the thermoelastic interactions in an isotropic and homogeneous semi-infinite medium with variable thermal conductivity caused by an ultra-short pulsed laser heating based on the linear nonlocal theory of elasticity has been considered. We consider that the thermal conductivity of the material is dependent on the temperature. The surface of the surrounding plane of the medium is...
متن کاملSelf-Consistent Analysis of Barrier Characterization Effects on Quantum Well Laser Internal Performance
In this paper, a numerical study of barrier characterization effects on the high-temperature internal performance of an InGaAsP multi-quantum well laser is presented. The softwareused for this purpose self-consistently combines the three-dimensional simulation of carrier transports, self-heating, and optical waveguiding. The laser model calculates all relevant physical mechanisms, including the...
متن کاملEXPERIMENTAL AND NUMERICAL INVESTIGATION ON LASER BENDING PROCESS
Laser bending is an advanced process in sheet metal forming in which a laser heat source is used to shape the metal sheet. In this paper, temperature distribution in a mild steel sheet metal is investigated numerically and experimentally. Laser heat source is applied through curved paths in square sheet metal parts. Finite element (FE) simulation is performed with the ABAQUS/CAE standard softwa...
متن کامل