Analyses of the temperature dependence of the DGD in optical cables
Author(s): Giovanna Borghi , A. Bessa dos Santos , J. P. von der Weid 
Affiliation(s):  Optical Metrology Division/Dimci/Inmetro,  Telecommunication Division/Dimci/Inmetro,  Center for Telecommunications Studies, Pontifical Catholic University of Rio de Janeiro
Topic: 1. Interferometry & Optical Testing Techniques
Nowadays, some effort has been made to measure and to compensate the effects of first order PMD where only one channel of optical links is analyzed. However, we observed that in WDM systems the channels have differences between the mean PMD values and the expected PMD large enough to cause outage in optical communications links. We analyzed the DGD x wavelength characteristic of a Hi-Bi fiber, which was used as PMD emulator, and of a spool of DS fiber (15km long). Several measurements were done at different temperatures and different PMD() characteristics were observed. The idea is not only to verify the temperature dependence in the PMD measurement as well as to evaluate if it is identical for all wavelengths. The PMD emulator was built positioning three piezo-electric elements built in a assembling capable of compressing the fiber and consequently generating a birefringence variation, thus changing the DGD x wavelength shape. This structure simulates the PMD of a commercial SMF used in optical communications. In order to correlate and evidence the results DS fiber was measured using the polarimetric method and the spool was measured inside an environmental chamber where the temperature was varied from -5oC up to 50oC.