Optimizing double-phase method based on gradient descent algorithm with complex spectrum loss function

This study proposes a gradient descent method for enhancing the quality of reconstructed images encoded by double-phase holograms (DPHs). Holographic displays are often noisy because of optical hardware problems. However, owing to the conversion from complex-amplitude holograms to phase-only holograms, the reconstructed images still have noise and cannot be ignored. In this paper, the proposed method uses a spectrum loss function instead of image loss function in the gradient descent optimization process. The spectrum loss function ensures that DPHs can be optimized by gradient descent method, and this method requires only several iterations. The simulations and experimental results have validated the effectiveness of the proposed method.