Abstract

Incoherent light, transmitted via multimode fibers, represents a potential carrier for information that is directly modulated on the light envelope. The amplitude and phase characteristics of the envelope (baseband) signal are affected by the fiber waveguide because of group delay differences among the modes. We report on a technique that determines the baseband frequency response of the fiber system by comparing the beat spectra of light from a free-running laser before and after transmission through the fiber. As an example, we describe the measurement of 30 m of cladded multimode fiber. The 3-dB bandwidth was 700 MHz, somewhat larger than predicted on the basis of the computed group velocity differences.

© 1972 Optical Society of America

Measurements of the Baseband Frequency Response of a 1-km Fiber

S. D. Personick, W. M. Hubbard, and W. S. Holden
Appl. Opt. 13(2) 266-268 (1974)

Baseband frequency response measurement system for optical components

M. Maeda, K. Nagano, Y. Minai, and M. Tanaka
Appl. Opt. 17(4) 651-654 (1978)

Measuring the complex frequency response of multimode optical fibers

T. Okoshi, J. C. Chang, and S. Saito
Appl. Opt. 20(8) 1414-1417 (1981)

Baseband frequency response of a graded-index fiber excited by a step-index fiber

Tsuneo Horiguchi, Tadatoshi Tanifuji, and Masamitsu Tokuda
Appl. Opt. 19(15) 2589-2596 (1980)

Material Dispersion in Optical Fiber Waveguides

M. DiDomenico
Appl. Opt. 11(3) 652-654 (1972)