Laser polishing of optical fiber end surface

A new application of glass surface treatment is presented. Fine polishing of optical fiber end (silica type), core/cladding surface is performed. A low-power monomode longitudinal 10-W continuous wave CO2 laser is used. Laser power density is 140 W/cm(2). The beam is spatially filtered to increase the beam uniformity. A decrease of the roughness from 2.5 mum average to less than 100 nm is achieved. The microstructure of the surfaces is studied using atomic force microscopy. An optimum irradiation time of exposure of 6 s is found. A loss decrease of 1.5 dB after laser irradiation is measured. Thus, a simple method to further decrease the optical fiber losses after mechanical polishing is put into evidence. This method is easy to apply to any type of optical fiber. Moreover, it is considered that for such polished fibers, when used in conjunction with a connector (FC/PC, ST, SC, APC, and DIN type connectors), the efficiency in any application increases. (C) 2001 Society of Photo-Optical Instrumentation Engineers.