Abstract

It has been shown that the fundamental mode spot size governs the splice loss¹ and the microbending loss² of single-mode fibers. Matsumura also showed³ that the equivalent step-index fiber has approximately the same transmission characteristics (bending loss, propagation constant, provided the actual Index profile Is not too far from a step). Thus a very simple measurement of the mode spot size is of primary importance. We report a simple method, requiring only a variable aperture camera lens added to the attenuation measurement apparatus and no further fiber handling: the variable aperture lens (VAL) method.

© 1982 Optical Society of America