Bragg diffraction properties of tunable cascaded volume holographic gratings

In this paper, we study the diffraction properties of tunable cascaded VHGs by using the two-dimensional coupled wave theory and two-dimensional Runge-Kutta methods. The intensity distributions of the diffracted and transmitted beams are given, the total diffraction efficiency is calculated for multiple cascaded finite-sized VHGs. It is shown that the diffraction characteristics depend on the grating parameters such as the number of the cascaded VHGs and the sizes of each VHG, and the effects of the buffer gaps between two cascaded VHGs is also discussed. It demonstrates the possibility of shaping beam and improving the beam quality by controlling the grating parameters and the layers number of the VHGs. The analysis of this paper also will be valuable for novel applications of finite-sized VHGs.