Effects of End-Face Tilt Angle on Numerical Aperture for Straight and Bent Plastic Optical Fibers

Abstract

Numerical aperture (NA) is an important parameter of optical fibers. The larger it is, the greater the amount of light input into the fiber and, hence, the greater the achievable transmission distance. In this article, analytical functions are given for numerical aperture of an angle-ended plastic optical fiber in terms of the tilt angle of its input/output face. This tilt may be intentional, as in biomedical spectroscopic sensors, or otherwise when exploiting the quick interconnectivity potential of plastic fibers. The influence of fiber curvature on its numerical aperture has also been quantified as the functions given cover both straight and curved fiber configurations.

Skew ray tracing in a step-index optical fiber using geometric algebra

“…But the system for naming these geometrical quantities vary from author to author, making it difficult to compare results. [3,[11][12][13][14] To solve the problem of the angle naming conventions, we define the directions of the vectors in terms of the polar angles θ and the azimuthal angle φ in spherical coordinates, distinguished only by their subscripts, e.g. θ σ and φ σ for the incident ray σ and φ η for the normal vector η.…”

Investigation of influence of tilt angle on mode dispersion in step-index plastic optical fibers

“…The angle−ended fiber and its mathematical model were described in Ref. 23. Using the same formalism, we now extend the work presented in Ref.…”

“…Using the same formalism, we now extend the work presented in Ref. 23 in order to investigate the influence of the tilt−angle on modal dispersion in SI POF.…”

“…Following the for− malism in Ref. 23, the "perturbed" numerical aperture in the case when the fiber is terminated with the tilt angle e can be expressed as …”