The invention provides a treatment device (100) for fractional laser-based treatment. The treatment device comprises a treatment generator (80) comprising a treatment laser (20) and a laser scanning system (30). The laser scanning system comprises at least one movable deflection element and is configured and arranged for scanning laser light across an emission window (70) towards skin tissue (110) from a plurality of locations (74) in the emission window by moving the at least one deflection element relative to the emission window, whereby, in use, laser-based lesions (120) are generated inside the skin tissue. The treatment device also comprises a controller (60) for generating a predefined disposition of lesions (120) in the skin tissue by emitting laser light via selected ones of the plurality of locations in the emission window while the treatment device is moved relative to the skin surface (105). The controller is configured for generating an area disposition of the lesions by scanning the laser light across the emission window using the laser scanning system and deflecting laser light into the skin tissue via the plurality of locations while the treatment device is moved relative to the skin surface, whereas in the line treatment mode the controller is configured to generate a line disposition of the lesions inside the skin tissue from a single predefined location of the emission window by maintaining the at least one deflection element in a stationary position relative to the emission window while the treatment device is moved relative to the skin surface.
