Loss-Increase mechanism of Secondary-Jacketed Optical Fibers at Very Low Temperatures

Yoshito SHUTO

Summary :

Based on the loss behavior of optical fibers coated with high and low thermal expansion coefficient (α) secondary jackets in the -180 to 20 temperature range, the mechanism of loss increase has been discussed. The low α liquid-crystalline-polyester(LCP)-jacketed fiber shows the microbending loss of 5 dB/km at -180, while the high α nylon-jacketed fiber exhibits the maximum microbending loss of about 30 dB/km at -120 and then shows the decrease in loss with decreasing temperature. The relatively low loss increase in the LCP-jacketed fiber arises from crystallization of the primary silicone and slight eccentricity of the LCP jacket. The unusual loss behavior in the nylon-jacketed fiber can be explained in terms of the arrangement of randomly distributed fiber curvature at -120, which is predicted by Yabuta's fiber-buckling model and supported by the occurrence of fiber-strain relaxation.

• Publication: IEICE TRANSACTIONS on Electronics Vol.E74-C No.6 pp.1683-1688
• Publication Date: 1991/06/25
• Type of Manuscript: PAPER
• Category: Opto-Electronics

Authors

Yoshito SHUTO

Keyword