Using a gradient curvature beam to tune a uniform fiber grating into a chirped one

摘要

Giving a new method to tuning a fiber Bragg grating into a chirped grating using a gradient curvature beam. Stick a FBG to an "S" shape beam with one end free and another give a pull. The curvature of the beam would change and the FBG get gradient strain. Thus we get the chirped grating while the central wavelength doesn't change. The design method and the theoretical analysis are given. The maximum chirped bandwidth in our experiment is 5.10nm and the central wavelength does not change.