Fine-tuning of the transmission characteristics of an arc-induced long-period fiber grating by local heating

A method for tuning the transmission characteristics of arc-induced long-period fiber gratings by local heating is presented. A traveling burner, produced by the combustion of a mixture of oxygen and butane, locally heats the longperiod grating producing a wavelength shift of the resonant peaks. We have found that the resonant wavelengths are blue-shifted during the first 7 round trips of the flame, but when heating process continues the notches shifts toward longer wavelengths. A fine and long range tuning of the resonant wavelengths up to 120 nm can be achieved without substantial degradation on the grating characteristics. The process is repeatable and only takes a few minutes.