We propose the use of polyvinyl alcohol photosensitized with copper chloride dihydrated CuCl₂(2H₂O) as a photosensitive material for recording holographic gratings. We obtained different dissolutions changing concentration of photosensitive agent and varying their pH factor, refraction index, and optical density for each sample. We registered diffraction gratings by holographic methods. The behaviors of diffraction efficiency parameters of holographic gratings regarding the concentration of a photosensitive agent were analyzed. We show there exists a correspondence between the diffraction efficiency parameter with concentration change of CuCl₂(2H₂O). The low toxicity of this holographic recording material as well as its peculiar behavior, photosensitivity, and ability to conduct electricity, makes it attractive for production diffractive optical elements with bio-polymers. ©2011 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.3589293]