Optimized phase-only hologram generation for high-quality holographic display

In holographic displays, the Gerchberg-Saxton (GS) method has been widely used to generate the phase-only hologram (POH). However, as the constraint strategy of the GS method cannot optimize the POH well enough, the display quality is degraded. Various methods have been proposed to solve this problem, such as introducing the dummy area, using an initial quadratic phase, and modifying the amplitude constraint strategy. This paper proposes a simple and effective iterative method to optimize POH for the high-quality reconstructed image, which is a combination of the above three methods. In the proposed method, the target image is padded with zeros, and the padded image is divided into the target and non-target region. The initial phase in the target region is reset to the quadratic phase, and the optimized parameters α and β are introduced to modify the amplitude constraint strategy. In the iterative process, this strategy is applied to the target region. Numerical and optical experiments were conducted to verify the effectiveness of the proposed method. The results show that the speckle noise is effectively suppressed, and the quality of the reconstructed image is improved.