Fabrication and application of a novel long period fiber grating with arched fiber cores

Abstract In this paper, the fabrication of arched fiber core based on single-mode fiber is first proposed and experimentally studied about the relevant sensing characteristics. A novel kind of long-period fiber grating (LPFG) with good sensing performance is formed by increasing the number of arched cores with a fixed cycle. The arched core long-period fiber grating (AC-LPFG) has excellent bending sensitivities with −25.06 nm/m−1, −4.26 nm/m−1, 16.84 nm/m−1, −4.92 nm/m−1 in four different directions, and it shows that the AC-LPFG can distinguish the bending direction very well. Meanwhile, the strain sensitivity and temperature sensitivity of the AC-LPFG are also experimentally tested to be −5.9 pm/μm and 84.5 pm/℃ respectively. The excellent bending and strain characteristics of the AC-LPFG indicate that the arched fiber core has similar effects as some special fibers, which will surely get closer attention and more research applications in the future.