Low V-number optical fibers: Secondary maxima in the far-field radiation pattern

Photoelectric and photographic techniques have been used to measure and display the intensities and positions of as many as six secondary maxima in the far-field radiation patterns of a variety of low V-number optical fibers. The effects of changing the shape of the refractive-index profile of the fiber core on the secondary maxima are investigated. The power distribution of the light propagating in the core region is compared to the refractive-index distribution.