In the process of laser plastic welding an infrared laser beam is passed through an upper laser transmissive layer to a lower laser absorbing layer. The energy absorbed at the weld interface is conducted from the lower layer to the upper layer through conduction as the parts are clamped tightly together.
Hybrid laser welding is the same concept, however, in addition to the laser radiation a high-powered halogen lamp assists the laser. The polychromatic radiation from the halogen lamp helps pre-heat and soften both the upper and lower layer. This makes for faster welding, less stress on the part and stronger welds.