In the tensor polarization holography theory, parameters A and B represent the scalar and tensor coefficients of the photo-induced change in the dielectric tensor, respectively. A/B is called the exposure response coefficient, a key factor for manipulating the polarization state of the reconstructed wave in polarization holography. We measure the initial exposure response coefficient of the polarization-sensitive material, phenanthrenequinone-doped polymethyl methacrylate (PQ/PMMA), and analyze the effect of the interference angle and the polarization states of the signal and reference waves on the coefficient in linear polarization holography. To better understand the linear polarization holography, we develop a formula to describe the law of the initial exposure response coefficient.