Bragg gratings and Fabry-Perot interferometers on an Er-MgO-doped optical fiber

In this paper, the fabrication of fiber Bragg gratings (FBGs) and intrinsic Fabry-Perot interferometers (IFPIs) on an Er-MgO-doped silica optical fiber is reported. The inscription of both sensing devices was performed by means of a femtosecond laser, using the phase mask method to inscribe the FBG and a micromachining platform for the IFPI. Thermal and strain characterizations were performed for both devices, achieving the maximum sensitivities of 12.57 pm/degrees C and 0.85 pm/mu epsilon for the FBG case, and 10.2 pm/degrees C and 0.91 pm/mu epsilon for the IFPI. A high temperature experiment was conducted to assess the thermal behavior of the inscribed FBG, revealing sensing capabilities for temperatures up to 700 degrees C. The results confirm that this new type of fiber will have an important role on the development of new optoelectronic devices, such as fiber lasers, optical amplifiers and sensors.