Using coaxial reflectors to transform multiple axisymmetric beams

A coaxial reflective optical system (CROS) is proposed for improving the spot size and combined-distance of multiple axisymmetric beams. As a reflective shaping system, the CROS can be easily designed for this aim using the method of the matrix optics. A numerical simulation of the transformed beams is presented and analyzed. The results show that multiple axisymmetric beams can be transformed to a new form with a smaller spot size and longer combined distance using the CROS. The method we proposed is simple and effectual in material processing.