Abstract

Optical fiber communications systems require a variety of optical components, such as directional couplers, switches, wavelength multiplexers, etc., and most of the components that have been reported to date use graded-refractive-index rod lenses (GRIN-rod lenses).¹ A very important parameter for the evaluation of such components is the insertion loss, and in most cases the major loss contributions are from imperfections of the lenses and from mechanical misalignments. In this paper we describe analysis techniques which make it possible to separate the effects of lens imperfections and misalignments, and from which we determine the lens characteristics required to achieve specified losses. We also review the various techniques available for measuring GRIN-rod lens characteristics, and compare the achievable accuracies of the techniques with that required for the analysis of fiber components.

© 1981 Optical Society of America