Photosensitivity and gratings in dye-doped polymer optical fibers

In this paper, we show experimentally that large photosensitivity in dye-do ped polymer optical fibers can be obtained with small pump power (about 1 m W) at visible wavelength. The fiber has two identical cores each doped with fluorescein, and the pump beam is launched axially into one of the cores. However, when the pump beam at UV wavelength is launched into the fiber tra nsversely, large photosensitivity is also observed. We also show that grati ngs can be written in polymer fiber and preform. (C) 1999 academic Press.