Fabricating triangular fiber Bragg grating using nonlinear one step method

摘要

A new method which makes use of the variable accelerated motion of servo motor is presented to fabricate the triangular fiber Bragg grating. Considering the exponential relationship between the changes of grating refractive index and the exposure of UV laser, this method only requires one exposure, the variable accelerated motion of servo motor is controlled by computer program to control the increment of UV laser exposure and the linear change of grating refractive index on the fiber axial, then the edge of triangular fiber Bragg grating can be gained. The experiment result shows that the edge of triangular fiber Bragg grating has a good linearity, the bandwidth is 1.6nm, the linear bandwidth which can be used is lnm, and the maximum reflectivity is 90%. As a fiber Bragg grating sensor demodulation device, triangular fiber Bragg grating will be more widely used in sensing fields.