Coupling characteristics of the spun optical fiber with multiple stress elements

Abstract

Abstract Possible coupling between fundamental modes and higher order modes in a spun optical fiber with multiple stress elements is analyzed. It shows that only the higher order H E mn mode with the opposite circular polarization state can be coupled with the fundamental H E 11 mode. The coupling between the fundamental H E 11 mode and the TE, TM or EH modes can never be occurred. In the possible coupling between H E mn mode and H E 11 mode, m should be equal to N-1, where N is the number of the stress elements. As a comparison, the coupling property in a spun optical fiber with single stress element is also demonstrated. In this case, the fundamental H E 11 mode can not only be coupled with the higher order H E 2 n mode but also can be coupled with the higher order T E mode.