Incoherent beam combining of multiple single-mode fiber lasers utilizing fused tapered bundling

Beam combining with tapered array of single mode fibers is presented. A mutual incoherent CW power launch into the entries introduces intensity addition of which brightness can be utmost conserved. The best limit for the combined output beam quality is given by the brightness conservation law. An experiment where three and seven input CW signals are combined supports this claim. The respective M² values were close to the best predicted limit, thus it is found to have good agreement with the brightness limit. The power transfer is higher than 90%.