Single Step Process for Optical Microfiber In-Line Mach-Zehnder Interferometers Fabrication

Abstract

Based on a novel modulated arc-discharge technique, a single step process for taper-functionalized optical microfiber in-line Mach-Zehnder interferometers (MZIs) fabrication is presented. By this process, microfiber and its added down-tapers are fabricated exploiting an amplitude modulated arc-discharge heating in one-step. In this letter, included short-time arc OFF switches during an arc-assisted microfiber fabrication process result in the formation of miniature down-tapers along the microfiber being pulled. The arrangement and time duration of these arc OFF pulses determine the functionality of the resultant microfiber structure. The first single step taper-functionalized microfiber in-line MZI exhibits an extremely high interference dip (29 dB) with low full width at half maximum (5 nm) and high external refractive index (RI) sensitivity of 1840 nm per RI unit around 1.368. © 1989-2012 IEEE.