Towards end-to-end 3D hologram generation strategy for holographic displays with transport of intensity equation

Holographic displays are widely regarded as the pinnacle of three-dimensional (3D) visualization technology. In these displays, real objects must be either photographed or converted into 3D models, which are then processed through neural networks or sophisticated algorithms to generate 3D holograms. To address this challenge, we propose an end-to-end 3D hologram generation strategy that integrates the Transport of Intensity Equation (TIE) phase retrieval technique with the Double Phase-Amplitude Coding (DPAC) method. Under coherent light illumination, phase-only holograms containing depth information can be directly generated by capturing out-of-focus amplitude maps of object light waves propagating to the holographic plane via a camera. The TIE module processes the two out-of-focus amplitude maps to resolve the phase and subsequently generates a phase-only hologram through DPAC. We further conduct simulations to validate the phase retrieval capability of the TIE on complex holograms and demonstrate the feasibility of our proposed strategy.