Fig. 1. Schematic of experimental setup

Fig. 2. Optical path map of imaging system

Fig. 3. Plasma morphology in hybrid welding with argon shielding gas. (a) P=1 kW; (b) P=1.5 kW; (c) P=2 kW; (d) P=2.5 kW

Fig. 4. Results obtained at power of 3 kW. (a) Characteristic of combustion wave supported by laser; (b) area fluctuation of the third image

Fig. 5. Plasma morphology in hybrid welding with helium shielding gas. (a) P=2 kW; (b) P=2.5 kW; (c) P=3 kW

Fig. 6. Dynamic behavior of plasma in hybrid welding with helium shielding gas when P=3 kW and I=150 A

Fig. 7. Plasma morphology in hybrid welding with helium shielding gas. (a) I=50 A; (b) I=100 A; (c) I=150 A