Abstract: A laser machining system adapted to reduce redeposition of material ablated from a workpiece. The laser machining system includes: a laser source to generate a pulsed laser beam; optics to relay the pulsed laser beam along a beam path from the laser source to the work piece; a long working distance objective disposed in the beam path; a workpiece holder to hold the workpiece such that an ablation surface of the workpiece is substantially vertical; and a vacuum chamber, including a window that is substantially transmissive to the laser beam. The vacuum chamber is sized and arranged such that the window in disposed in the beam path and the vacuum chamber encloses the workpiece holder in a reduced pressure environment. The long working distance objective substantially focuses the laser beam to a beam spot on an ablation surface of the workpiece.