Measured attenuation and depolarization of light transmitted along glass fibers

Loss measurements have been made on glass fibers immersed in index matching oil. The measurements include state of polarization analyses of the light leaving fiber ends. The character of the beam was determined by using α λ/4 plate in conjunction with a polaroid analyser to measure the components of unpolarized and polarized light. The data indicates that unclad fibers attenuate light much more than similar glass clad fiber waveguides. Mode purity within a multimode glass fiber was estimated from measurements of the admixture of modes leaving its end. Light guided along unclad fibers was considerably less distorted than light propagating along similar clad waveguides.