Axial strain effects on optical fiber mode patterns

Axial strain effects in multimode fibers are studied. A few-mode fiber is mounted on a tensile testing machine and strained at various speeds. The output of a monochromatic light source passing through it is monitored and recorded. Relations are noted between the light output the magnitude of tension and the rate of the applied axial strain. Flexural behavior of the optical fiber at various tensions is also studied by monitoring the modal output pattern. Relations are compiled to serve as a beginning to model these and other related modal effects. A theoretical background is also suggested to explain the observed effects.