In-line all-fiber Fabry-Perot and Mach-Zehnder interferometers formed by hollow fiber with lateral offset

Abstract

Two kinds of novel in-line all-fiber interferometers, including tip Farby-Perot interferometer and compact Mach-Zehnder interferometer, are proposed and demonstrated by automatically fusion splicing a short section of hollow fiber to the end of a single-mode fiber (SMF) and sandwiching a section of hollow fiber in two section of SMF with a tiny intentional lateral offset that induces the optical path difference (OPD) required to form the two interferometers, respectively. Temperature responses of both the two interferometers are studied experimentally. It is anticipated that such an easy making, compact and low cost fiber-optic interferometers could find important applications in practice.