A device for welding together optical fiber, constructed and put into practice, according to the principles of this invention, comprises a photon source capable of transmitting photons to at a desired waveband to a desired target, e.g., a solid state part, a fiber optic cable, or a optical waveguide. The desired target, e.g., the end of an optical fiber, comprises a photon absorber material that is designed to absorb the photons emitted by the photon source. Through exposure of the photons emitted from the photon source, the absorber is caused to melt within a very short period of time for a defined period of time, during which time the desired target parts are joined and welded together. Ideally, the photon absorber material is matched to absorb photons in the same waveband as that emitted by the photon source. The device is configured to efficiently produce, focus, and deliver photons to the target area for welding.