A printing system is disclosed which comprises a writing module, and a member having an imaging surface configured to carry a polymer and movable relative to the writing module. The writing module is configured to direct onto the imaging surface a plurality of individually controllable light beams that are spaced from one another in a direction transverse to the direction of movement of the imaging surface, incidence of a light beam on a spot on the imaging surface serving to soften or liquefy the polymer carried by the imaging surface at the spot. The polymer softened or liquefied at the spot can transfer to a substrate or serve as an adhesive on the imaging surface. The writing module comprises a plurality of integrated electronic modules each having an array of individually controllable light sources, each light source producing a respective one of the light beams. In the invention, each light source comprises at least two Vertical-Cavity Surface-Emitting Laser (VCSEL) light-emitting semiconductor junctions connected in series with one another and configured to direct light onto the imaging surface at the same spot as one another.