Fiber Inline Core-Cladding-Mode Interferometer Fabricated by CO₂ Laser Irradiation

Abstract

A fiber inline Michelson interferometer was fabricated by micromachining a step structure at the tip of a single-mode optical fiber using a femtosecond laser. The step structure splits the fiber core into two reflection paths and produces an interference signal. A fringe visibility of 18 dB was achieved. Temperature sensing up to 1000 °C was demonstrated using the fabricated assembly-free device