Numerical Simulation Of The Imulation Crystal Rystal Growth Of Ti:al Rowth Al2o3 Material By The µ -pd Technology

In this work we have studied the growth of titanium doped sapphire using the micro-pulling down technique; we established a numerical, two-dimensional finite volume model in cylindrical coordinates with an axisymmetric configuration. The flow, the heat and the mass transfer are modeled by the differential equations of conservation of mass, momentum, energy and species. This problem, which takes into account the convection-diffusion coupling, is discretized using the Finite Volumes Method. Simulation results show that the longitudinal distribution of titanium remains homogeneous along the axis of the sapphire material. The radial mass transfer of titanium increases in the crystal when the pulling rate increases. This important result contributes to strengthen the coupling of the laser beam with the active ions and allows a highest laser output power. The melt/crystal interface for the µ-PD technique has a flat shape; this flatness of the interface shape agrees with the experiment observation and is very important since it shows that drawing conditions are very stable. Our model for the µ-PD method is in good agreement with experimental results.