Azimuthally symmetric longperiod fiber gratings fabricated with CO2 laser

Two methods for fabrication of azimuthally symmetric long-period fiber gratings (LPFGs) with CO2 laser arc presented. These methods are based on symmetric exposure of the laser beam and rotation of the fiber, and the measured polarization-dependent losses (PDL) are comparable to that of the normal fiber. (C) 2004 Wiley Periodicals, Inc.