Brillouin lasing in single-mode tapered optical fiber with inscribed fiber Bragg grating array

A tapered optical fiber has been manufactured with an array of fiber Bragg gratings (FBG)inscribedduring the drawing process. The total fiber peak reflectivity is 5% and the reflection bandwidth is ∼3.5 nm. A coherent frequency domain reflectometry has been appliedfor precise profiling of the fiber core diameter and grating reflectivity both distributed along the whole fiber length. These measurements are in a good agreement with the specific features of Brillouin lasing achieved in the semi-open fiber cavity configuration.