A new approach for tuning the wavelength of a fiber Bragg grating without chirping is demonstrated. Tuning is achieved by bending a triangular cantilever beam with the grating was epoxied on its surface. The isosceles triangle was firmly fixed at its base and bending was realised by exerting a force to its vertex. Chirp-free tuning of a fiber Bragg grating over a wavelength range of 4.52nm is demonstrated. Using a correction index of 0.7, the experimental results are in good agreement with thetheoretical values.

Heat treatment with the presence of hydrogen (H2) that react with GeE' centers (Ge) at high tern perature will weaken the refractive index modulation of grating fabricated in hydrogen loaded normal germanosilicate fiber. Pre. annealing treatment of the above fiber was demonstrated to be able to enhance the grating's thermal stability effectively．0.37-nm blue-shift of the reflected Bragg wavelength was ob-served．