Abstract: A mirror for systems for utilization of solar energy, with a substrate of low absorption flat glass and a rear highly reflective silver reflective layer is provided with a protective layer, a process for its manufacture and its use. In order to render this mirror usable for solar chemical energy utilization as well as to improve the energy yield overall, according to the invention the substrate is provided on its front with a high refractive index dielectric UV reflective layer of a thickness such that it acts as a reflection enhancing interference layer for the near UV region.

Abstract: The efficiency of laser welding and other laser material processing is optimized according to this invention by rotating the plane of polarization of a linearly polarized laser beam in relation to a work piece of the material being processed simultaneously and in synchronization with steering the laser beam over the work piece so as to keep the plane of polarization parallel to either the plane of incidence or the direction of travel of the beam in relation to the work piece. Also, depending to some extent on the particular processing being accomplished, such as welding or fusing, the angle of incidence of the laser beam on the work piece is kept at or near the polarizing or Brewster's angle. The combination of maintaining the plane of polarization parallel to plane of incidence while also maintaining the angle of incidence at or near the polarizing or Brewster's angle results in only minimal, if any, reflection losses during laser welding.