Example for Laser Development
In the first step the laser device geometry is defined either directly
in Comsol or by importing it from a CAD file. It might be useful to
reduce the simulation volume with respect to symmetry planes
in order to save up computer resources and to speed up the process.
In the next step the mesh is chosen properly depending on the
geometry of its components and the physical phenomena involved.
Pump light propagation and absorption
Subsequently, the pump laser source needs to be implemented
in the simulation. Ray tracing can be used to propagate the pump
light and determine its absorption in the laser crystal.
As a result of the absorbed pump light the gain profile within
the laser crystal is determined.
Laser light propagation and emission
In the following step, the laser light propagation inside of the laser cavity
as well as the laser beam emission is simulated by means of ray tracing.
Finally, the FEM based calculation of the temperature distribution
resulting from heat generation and dissipation is performed.
In order to account for the influence of an inhomogeneous
temperature distribution inside of the laser crystal (thermal lensing)
on the pump and laser light, the simulation steps are repeated
in multiple iterations.