Investigations on the characteristics of point-by-point CO/sub 2/ laser induced long-period grating on optical fiber

An effective, simple, and low cost fabrication of Long-period fiber gratings (LPFGs) using point-by-point method by CO/sub 2/ laser was investigated and demonstrated. The B-Ge codoped fiber was used to produce a peak attenuation loss of at least 20 dB with period number of 17. Monitoring on the variation of spectral responses with the change of temperatures in the range of 25/spl deg/C to 250/spl deg/C had been observed. Below 100/spl deg/C, the spectral response was nearly stable. An approximate sensitivity of 0.0186 nm//spl deg/C was obtained in 100/spl deg/C to 160/spl deg/C temperature range. It exhibited a double sensitivity response to approximately 0.0378 nm//spl deg/C in the 170/spl deg/C to 250/spl deg/C range.