Laser heating of thick layers through the backwards, self-sustained propagation of a steep and steady state thermal front

M. Bruel (1)

1 Aplinov

We investigate theoretically a mode of heating layers using a laser beam. In this mode thermal energy, the temperature of the layer, propagates in a steady-state self sustained fashion from the bottom of the layer towards the surface and may exhibit a very steep front. The propagation exhibits a constant speed, related to the intensity of the power flux. To achieve this heating mode the absorption coefficient has to remain low in low temperatures and increase rapidly as a function of temperature in higher temperatures. Additionally, a significant temperature increase must be generated to trigger this propagation mode, for example through the presence of a strongly absorbing layer beneath the transparent layer. The mode is well suited to semiconductors, especially silicon. A few examples of applications are proposed.

Mots clés: Physical Sciences

M. Bruel. Laser heating of thick layers through the backwards, self-sustained propagation of a steep and steady state thermal front. European Physical Journal: Applied Physics, 2008, 45 (1), pp.1. ⟨10.1051/epjap:2008190⟩. ⟨hal-00480184⟩