Image quality enhancement for holographic display via dual-tilted phase light modulators

Abstract

Texas Instruments Phase Light Modulators (TI-PLM) is a MEMS based device for modulating the phase of light. It plays an important role in computational holographic display. However, due to its relatively large pixel pitch (10.8 um for 0.67 VIS PLM) and limited phase modulating levels (16 levels), the image quality suffers from speckle noise and insufficient phase representation. In this paper, we propose an optical architecture that combines two tilted PLMs with opposite tilt angle, such tilt allows the supported frequency spectrum to be enlarged, furthermore, stochastic gradient descent (SGD) along with tilt angular spectrum method (ASM) are utilized for CGH generation which allows constructive interference between the two fields from dual tilted PLMs. At the same time, LUT-aware Gumbel-softmax quantization and time multiplexing are employed for further optimization to ensure a high fidelity computational holographic display. Simulation and experimental results demonstrate the feasibility of the proposed method. This method provides a potential for futuristic near-eye holographic display with enhanced image quality.