Open AccessReduction of Birefringence and Polarization- Dependent Loss of Long-Period Fiber Gratings Fabricated with a KrF Excimer Laser
Author(s) -
Seung Tae Oh,
WonTaek Han,
Un-Chul Paek,
Youngjoo Chung
Publication year - 2003
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.11.003087
Subject(s) - materials science , optics , excimer laser , birefringence , long period fiber grating , laser , fluence , excimer , fiber laser , ultraviolet , polarization (electrochemistry) , optical fiber , optoelectronics , fiber , fiber optic sensor , wavelength , polarization maintaining optical fiber , composite material , chemistry , physics
We discuss the effect of UV laser exposure time, repetition rate, and heating by a heating coil on the resonance peak depth and polarization-dependent loss (PDL) of long-period fiber gratings (LPFGs). The LPFGs were fabricated with a KrF excimer laser and an amplitude mask. We observed an initial increase of the resonance peak depth and PDL as the UV exposure time was increased, which eventually decreased in response to over-coupling. With the total UV fluence kept constant, the peak depth continued to increase as the repetition rate was increased beyond 10 Hz, whereas the maximum PDL decreased when the repetition rate was higher than 17 Hz. This is believed to be a thermal effect caused by the rapid delivery of UV laser pulses. We observed a similar reduction of the maximum PDL from 1.35 to 0.25 dB when the fiber was heated by an adjacent heating coil.