The resonance wavelength-tuning characteristic of the arc-induced LPFGs by diameter modulation

In this paper, we fabricated the arc-induced long period fiber grating (LPFG) by core and cladding diameter modulation. The torsion experimental results demonstrate wavelength tunability by torsion directions. The resonance wavelength of the LPFG shifts toward the longer wavelength by about 8 nm with counterclockwise torsion and toward the shorter wavelength by about 10 nm with clockwise torsion. The LPFGs obtained by this fabrication method can be used as optical devices for tunable filtering or sensor applications.