An optical surgical probe includes a handpiece having a metal cannula at a distal end, a light guide within the metal cannula that carries a light beam from a light source through the metal cannula, and a multi-spot generator formed within a distal opening of the metal cannula that seals the distal opening of the metal cannula. The multi-spot generator includes a proximally-facing faceted end surface spaced from a distal end of the light guide that includes at least one facet oblique to a path of the light beam and a ball lens located distal to the faceted end surface. A high-conductivity ferrule surrounds the distal end of the light guide, is in thermal contact with the metal cannula, and includes a side-shield portion extending beyond the distal end of the light guide. The ferrule shields the cannula from a portion of the light beam reflected by the faceted end surface.