jectory is no longer restricted in one single direction, being wire-axial or deflected, but could be programmed to swing by real-time matching the laser pulse energy and phase. This means that the weld pool profile and bead formation may be actively controlled without adjusting the arc variables. Conclusions A pulsed fiber laser was selected to control the metal transfer in GMAW process in this study. The laser beam was focused into a tiny spot in order to achieve high-power density, to aim at the droplet. With these conditions, the following was found: 1. The high-power-density laser induces intensive vaporization on the local surface of the liquid droplet being irradiated. The laser recoil pressure can drive the droplet to wave. The vector of the vapor jet is coincident with the norm of the irradiated local surface. 2. When a continuous laser with a relatively limited power is applied, the droplet is repelled and elongated. The droplet is driven to wave and finally detached. The diameters of the detached droplet are smaller than those measured without a laser. The droplet detachment is slightly enhanced by 250-W laser irradiation. 3. Pulsed laser leads to significantly increased power density. Currentindependent metal transfer is realized for the first time, thanks to the irradiation of the pulsed laser. The pulsed laser controlling method also brings better controllability on metal transfer frequency, since the one drop per pulse metal transfer can be produced in synchronization with the laser pulse. The optimal laser incident point is at the droplet neck. 4. The mechanism of lasercontrolled metal transfer primarily lies in the cutting effect. The droplet neck is melted, vaporized, thinned, and finally cut off by the laser. Certain droplet deflection is associated with single-sided laser irradiation. Future double-sided laser irradiation may further ensure entirely new controllability on the droplet flying trajectory. 5. 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