A system for printing to form a three-dimensional object, using an additive process, where successive layers of material are formed into the three-dimensional object, the system comprising: a. a laser light source that comprises a laser diode array and an optical fiber that collects pump light from the laser diode array, wherein the optical fiber outputs a coherent beam of visible light, having a wavelength between 380 nm and 760 nm, in said optical fiber with a Rayleigh loss that is less than about 50 decibels per kilometer (dB/km); b. a substrate in optical communication with said laser light source; wherein the substrate comprises a metallic material; c. a scanning module downstream of said laser light source, wherein said scanning module is adapted to generate a predetermined scanning motion of said beam of visible light with respect to said substrate, which predetermined scanning motion corresponds to a shape of said three-dimensional object; d. a computer control system operatively coupled to said laser light source and said scanning module, wherein said computer control system is programmed to (i) control said scanning motion in a predetermined manner and (ii) modulate a power of said laser light source, to form said object from said substrate; and e. wherein said fiber comprises (i) a central core that is substantially single mode, (ii) a cladding of larger diameter than the central core that captures said plurality of beams of visible light outputted from said laser diode arrays, and (iii) an outer cladding that guides said coherent beam of visible light outputted by said laser diode array along said fiber. a. a laser light source that comprises a laser diode array and an optical fiber that collects pump light from the laser diode array, wherein the optical fiber outputs a coherent beam of visible light, having a wavelength between 380 nm and 760 nm, in said optical fiber with a Rayleigh loss that is less than about 50 decibels per kilometer (dB/km); b. a substrate in optical communication with said laser light source; wherein the substrate comprises a metallic material; c. a scanning module downstream of said laser light source, wherein said scanning module is adapted to generate a predetermined scanning motion of said beam of visible light with respect to said substrate, which predetermined scanning motion corresponds to a shape of said three-dimensional object; d. a computer control system operatively coupled to said laser light source and said scanning module, wherein said computer control system is programmed to (i) control said scanning motion in a predetermined manner and (ii) modulate a power of said laser light source, to form said object from said substrate; and e. wherein said fiber comprises (i) a central core that is substantially single mode, (ii) a cladding of larger diameter than the central core that captures said plurality of beams of visible light outputted from said laser diode arrays, and (iii) an outer cladding that guides said coherent beam of visible light outputted by said laser diode array along said fiber. (i) a central core that is substantially single mode, (ii) a cladding of larger diameter than the central core that captures said plurality of beams of visible light outputted from said laser diode arrays, and (iii) an outer cladding that guides said coherent beam of visible light outputted by said laser diode array along said fiber.