A fabrication method of long period fiber gratings(LPFGs) that can be easily controlled resonance wavelength and losses is introduced. In this paper, arc-induced superposition LPFGs were fabricated by core and cladding diameter modulation applying a n...
A fabrication method of long period fiber gratings(LPFGs) that can be easily controlled resonance wavelength and losses is introduced. In this paper, arc-induced superposition LPFGs were fabricated by core and cladding diameter modulation applying a number of small electric-arc to the normal fiber. We derived an equation of resonance wavelength change according to core diameter variation using the phase matching condition and showed the calculated results are well matched with experiments. And we show that the measured resonant wavelengths of arc-induced superposition LPFGs according to grating period are well coincident with that of phase matching condition. The resonance wavelength is measured for the temperature changes and a slight mechanical strength degradation of arc-induced LPFGs is observed by increasing arc times. It was demonstrated that wavelength tunability of LPFGs by torsion directions and tension. And LPFGs were used to gain flattening filter for EDFA. It was proposed that optical sensor system for sensor applications using LPFGs.