Abstract

The power launching into multimode optical fibers with any profile of refractive index is analyzed by means of the geometrical optics. First two formulas of the numerical aperture are obtained, one including and the other excluding the contribution of leaky skew rays. Each one of these two numerical apertures has a certain domain of application, and the launching efficiencies from incoherent sources into optical fibers are calculated in both cases. Useful formulas and plots of launching efficiency for a few refractive index profiles are given. Finally the power losses due to source-fiber coupling errors (separation, displacement, or misalignment) are evaluated, and an interesting effect of virtual lengthening of the fiber is found.

© 1976 Optical Society of America

Leaky modes in graded index optical fibers

Robert Olshansky
Appl. Opt. 15(11) 2773-2777 (1976)

Pulse separating in transmission characteristics of multimode graded index optical fibers

Masahiro Ikeda and Haruo Yoshikiyo
Appl. Opt. 15(5) 1307-1312 (1976)

Dependence of output near-field beam profile on launching conditions in graded-index fibers used in delivery systems for Nd:YAG lasers

Alvaro A. P. Boechat, Daoning Su, and Julian D. C. Jones
Appl. Opt. 32(3) 291-297 (1993)

Pulse broadening in graded-index optical fibers

Robert Olshansky and Donald B. Keck
Appl. Opt. 15(2) 483-491 (1976)

Ray launching and observation in graded-index optical fibers

Kevin F. Barrell and Colin Pask
J. Opt. Soc. Am. 69(2) 294-300 (1979)