“Nanostructured surfaces”

Model calculations of nanolayer heating of a substance under the action of irradiation
L.V. Shmeleva, A.D. Suprun
 Department of Theoretical Physics, Faculty of Physics, Taras Shevchenko National University of Kyiv. Volodymyrska Street, 64/13, Kyiv-01601, Ukraine. 
E-mail: lshmel@univ.kiev.ua 

The paper considers the process of laser heating of a local area of an arbitrary metal surface. In previous researches, we studied the processes accompanying such an effect. The previously developed model takes into account both the elastic response of the medium and the temperature response to a powerful external impact. 
The modeled temperature dependences were analyzed for several technological applications using asymptotic approximations. In fact, the general analytical solutions depend on the coefficients of reflection and scattering of radiation by the surface, and these coefficients themselves also have a significant temperature dependence. As a result, the obtained equations for describing the surface heating process transform to transcendental. This leads to the need to use numerical methods to refine the temperature dynamics of the surface under intense laser irradiation.
Theoretical and numerical prediction of the results of laser exposure, both destructive and non-destructive, on various surfaces of materials today is extremely important. Laser technologies are used in many areas. Currently, one of the important areas is research related to the use of optical sensors. Here the laser ray falls on a metal layer of nanoscale thickness. Since the accuracy of such sensors is important, the effect of temperature on measurement results must be investigated. Considering that the thicknesses of the films used in surface plasmon resonance sensors are nanosized, the problem is further complicated. This is due to taking into account the dependence of the temperature of the nanosized metal layer on the absorption coefficient. These studies have been carried out and analyzed in the work.
The temperature dependences of the heating of a smooth (mirror) nanolayer and a nanolayer with irregularities or foreign inclusions was calculating in this proceedings. The obtained results are compared with previous results, where the temperature dependence of the optical coefficients was not considered.