Photoerasure of ultraviolet-induced birefringence and polarization-mode dispersion of chirped fiber Bragg gratings

The first, to my knowledge, experimental demonstration of photoerasure of UV-induced birefringence and polarization-mode dispersion (PMD) in chirped fiber Bragg gratings is presented here. The photoerasure process carried out by launching high-peak-power (approximately 0.6-kW) pulsed (10-Hz, 5-ns) circularly polarized laser light in the visible wavelength (532 nm) through the core of a fiber with the grating was found to reduce its PMD by more than 85% to 0.12 ps. Possible reasons for the photoerasure process, including photobleaching of UV-induced absorption and randomization of dipole orientation of UV-induced defects, are discussed.