In this work, we present an experimental and numerical analysis of spectral response of a fiber Bragg grating (FBG) written in a PANDA Polarization‐Maintaining Fiber (PMF) when the central region of the grating is perturbed by a diametrical load applied along of a direction defined with respect to the slow axis of the PMF. Due to the complex structure of the fiber, a finite element model was carried out to determine the strain distributions generated in the perturbed region of PMF. The FBG spectral response was theoretically evaluated using improved transfer matrix formalism, including a term in this formalism that allows to consider the induced rotation of the principal optical propagating axis. We have found experimentally and by numerical simulations that the reflected grating spectra for short FBG exhibit a narrow and tunable polarization‐dependent transmission band. The tuning of the spectral response of this band is linearly dependent of the magnitude and the angle of the applied force over the optical fiber.