The optical performance of photorefractive cells of liquid crystals strongly depends on the alignment of liquid crystals stabilized by surface states. Two photo-aligned polymer layers with relatively weak anchoring energy were investigated by FT-IR and UV/VIS spectroscopies. The cells without alignment layers showed significant scatterings due to random switching under an applied field. The cells with photo-alignment layers showed the high transmittance because of the high orientation order, but a little decrease in gain coefficient and diffraction efficiency because of the decrease in trap sites. Therefore, it is concluded that the reorientation of liquid crystals onto photo-conduction layer would govern the photorefractivity in two-beam coupling experiments. (C) 2002 Elsevier Science B.V. All rights reserved.