Machining device comprising: - a light source; - an optical system for obtaining from an incoming light beam an outgoing light beam that is spatially offset with respect to said incoming light beam, said optical system comprising: o a mirror: ▪ having a substantially flat reflecting surface defined by a normal for obtaining a first reflected light beam from a first incident light beam stemming from said incoming light beam, ▪ movable such that its normal is able to depict a trajectory in a three-dimensional space; said optical system being configured such that said first incident light beam and said normal to the movable mirror are separated by an angle comprised between 0° and 15° for all possible positions and orientations of said movable mirror; o driving means for moving said movable mirror; o a retro reflection system: ▪ positioned with respect to said movable mirror for obtaining from said first reflected light beam a second incident light beam on said mirror for all possible positions and orientations of said movable mirror, for obtaining an outgoing light beam from a reflection of said second incident light beam on said mirror, and ▪ able to provide said second incident light beam on said movable mirror that is parallel to said first reflected light beam for all possible positions and orientations of said movable mirror; - focusing means for focusing said outgoing light beam on a target. - a light source; - an optical system for obtaining from an incoming light beam an outgoing light beam that is spatially offset with respect to said incoming light beam, said optical system comprising: o a mirror: ▪ having a substantially flat reflecting surface defined by a normal for obtaining a first reflected light beam from a first incident light beam stemming from said incoming light beam, ▪ movable such that its normal is able to depict a trajectory in a three-dimensional space; said optical system being configured such that said first incident light beam and said normal to the movable mirror are separated by an angle comprised between 0° and 15° for all possible positions and orientations of said movable mirror; o driving means for moving said movable mirror; o a retro reflection system: ▪ positioned with respect to said movable mirror for obtaining from said first reflected light beam a second incident light beam on said mirror for all possible positions and orientations of said movable mirror, for obtaining an outgoing light beam from a reflection of said second incident light beam on said mirror, and ▪ able to provide said second incident light beam on said movable mirror that is parallel to said first reflected light beam for all possible positions and orientations of said movable mirror; o a mirror: ▪ having a substantially flat reflecting surface defined by a normal for obtaining a first reflected light beam from a first incident light beam stemming from said incoming light beam, ▪ movable such that its normal is able to depict a trajectory in a three-dimensional space; said optical system being configured such that said first incident light beam and said normal to the movable mirror are separated by an angle comprised between 0° and 15° for all possible positions and orientations of said movable mirror; ▪ having a substantially flat reflecting surface defined by a normal for obtaining a first reflected light beam from a first incident light beam stemming from said incoming light beam, ▪ movable such that its normal is able to depict a trajectory in a three-dimensional space; o driving means for moving said movable mirror; o a retro reflection system: ▪ positioned with respect to said movable mirror for obtaining from said first reflected light beam a second incident light beam on said mirror for all possible positions and orientations of said movable mirror, for obtaining an outgoing light beam from a reflection of said second incident light beam on said mirror, and ▪ able to provide said second incident light beam on said movable mirror that is parallel to said first reflected light beam for all possible positions and orientations of said movable mirror; ▪ positioned with respect to said movable mirror for obtaining from said first reflected light beam a second incident light beam on said mirror for all possible positions and orientations of said movable mirror, for obtaining an outgoing light beam from a reflection of said second incident light beam on said mirror, and ▪ able to provide said second incident light beam on said movable mirror that is parallel to said first reflected light beam for all possible positions and orientations of said movable mirror; - focusing means for focusing said outgoing light beam on a target.