Theoretical basis of transmission laser welding
Through-Transmission Laser Welding of Composites

Laser welding of thermoplastic polymers (figure 10 a) is relatively simple to achieve. The laser transmits almost all the energy to the weld interface, with only a small amount of energy reflected back to the surface of the transparent part.

Unlike polymers, which are homogeneous materials, thermoplastic composites are heterogeneous materials (figure 10 b) composed of fibers (very often glass fibers) and a thermoplastic matrix. This heterogeneity creates a strong interaction with the laser beam. Like light on the surface of a swimming pool...