A non-contact laser/ultrasonic welding technique for strengthening the con laser weld by the addition of ultrasonic cavitation and cleaning. A high powered laser applies heat to a weld joint to produce a melt. The output of the laser, or a second laser, is amplitude modulated to generate acoustic waves in the melt. The improved interdiffusion of the melt and the homogeneity of the weld joint result in an improved quality laser weld.