Filament Based Fabrication and Performance Analysis of Fiber Bragg Grating Sensors Using Ultrashort Pulse Laser

Abstract

The method of ultrashort pulse filamentation induced refractive index modification is employed to inscribe fiber Bragg grating (FBG) in singlemode optical fiber (SMF). Linebyline index inscription technique is used to write refractive index modulation in the core of SMF. The proposed pulse filamentation based index modification enables controlled and flexible writing of FBGs in optical fibers. Performance analysis of the fabricated FBG has been carried out for temperature, contact force, pressure, and axial strain sensing. The infiber FBG exhibits sensing performance very similar to FBGs commercially available to date. Then, the written FBG is engineered to demonstrate highly sensitive contact force sensor.