ROTATING FIBER OPTIC COUPLER FOR HIGH POWER LASER WELDING APPLICATIONS

A laser welding apparatus for clad welding the interior surface of a tube includes a rotating sleeve that encloses a fiber optic cable. A stationary laser generates light energy for the welding operations performed by the rotating sleeve. An optical coupler is positioned between the stationary laser and the rotating sleeve. A fixed optical assembly of the optical coupler receives light energy from the stationary laser and produces collimated and focused light energy. A rotating cable interface assembly of the optical coupler receives the collimated and focused light energy from the fixed optical assembly and applies it to the fiber optic cable of the rotating sleeve, which delivers the light energy to the interior surface of a tube so that it may be used to produce a clad weld. The fixed optical assembly includes axial and concentric alignment devices. The rotating cable interface assembly includes concentric alignment means and a monitoring cavity to provide optical feedback regarding the alignment between the fixed optical assembly and the rotating cable interface assembly. The rotating cable interface assembly may be constructed to include a safety fiber optic with an accompanying safety fiber optic photocell which is used to assess whether excessive light energy from the laser is being used.