Numerical Simulation of Laser Beam Propagation in High Aspect Ratio Channel

Laser beam propagation in high aspect ratio channels has been simulated by solving two-dimensional Maxwell wave equation with the finite element method. It has been found that the optical polarization direction has a very important effect on laser beam propagation in the channel, and under certain polarization direction the laser beam profile may keep changing in a very complicated way as the beam propagates through the channel. The above important effects, revealed by the numerical simulation in this paper, need to be considered to realize an accurate modeling or a good process design for laser machining of high aspect ratio microstructures.