Improved device and method for safe, accurate, efficient surgical procedures are disclosed. A preferred device is a waveguide assembly for delivering electromagnetic radiation to a tissue comprising a waveguide with a multi-facetted tip and a cap over the 5 multi-facetted tip. Preferably the waveguide is an optical fiber. The cap is a protective, reinforced cap fused to the optical fibers tip as an integral part of it and comprises an axially-extending portion oriented at a predetermined angle relative to the elongated axis of the optical fiber. A method of manufacturing special waveguide caps is provided. The optical fiber assembly delivers high power electromagnetic radiation in lateral direction 10 with respect to the elongated axis of the optical fiber, determined by the multiple-facetted tip, the slant angles of the optical fibers core, and the orientation of the caps axially-extending portion. A method for removing unwanted tissue like in benign prostatic hyperplasia treatments is also provided.
