Study of the Effects of Bending and Microbending on Glass Fibers.
Abstract
Single mode fibers are being used as media for acoustic sensors based on optical phase change detection. Deployment of this type of sensor requires the optical fiber to be tightly coiled around a small diameter mandrel. This tight coiling has been found to increase the fiber attenuation through bending and microbending loss mechanisms. As a result, ITT EOPD was awarded contract N00014-78-C-0852 by the Office Naval Research, which allows for an investigation of mechanisms of optical losses in glass fibers under states of bending an microbending and a study of relationships between optical loss mechanisms and glass composition for development of low loss wide aperture fibers. Both high and low NA single mode fibers were fabricated using core compositions of SiO2/GeO2 and SiO2/P2O3. The fiber performs were fabricated both by the conventional one-step technique and also by a two-step rod-in-tube technique, in order to reduce waveguide imperfections. The fibers in this array of eight different fiber types were evaluated for attenuation while unstressed, attenuation when bent around a mandrel, and attenuation while subjected to microbends. While the low NA fibers of all types showed significant bend and microbend induced losses, the high NA fibers showed very induced losses. The one-step high NA germanosilicate core fiber exhibited negligible bending and microbending losses under all circumstances. The one-step high NA germanosilicate core fiber was selected for the jacket evaluation. When 30 m of high NA fiber were wrapped around an 8 mm mandrel, the resulting attenuation increase was less than 0.3 dB.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 28, 1979
- Accession Number
- ADA081239
Entities
People
- Frank I. Akers
- Steven L. Mahurin