Enhanced diffraction efficiency of arbitrary higher order by using a thermoplastic plate is described. Such an enhanced diffraction efficiency is obtained by adjusting the angle between the two recording beams so that the diffraction angle of the desired order is tuned to the angle at which a thermoplastic plate gives the maximum frequency response and optimizing the exposure time. Using this method, any order can be selectively enhanced with the diffraction efficiency comparable to that of maximum attainable first order. Also, competition between different orders are sensitively affected as the tuning angle varies.