Long tapered fiber with array of FBG

摘要

A tapered optical fiber with an adiabatic transition from single-mode to a few-mode part has been fabricated with an array of fiber Bragg gratings being inscribed during the drawing process. We demonstrate that the propagating optical signal remains single-mode along the tapered fiber FBG array even in a multimode part of it. The spectral width of the reflected signal from the tapered optical fiber is 4 nm. The level of the reflected signal is up to 5% at some wavelengths.