Coded coherent diffraction imaging with reduced binary modulations and low-dynamic-range detection

Opt Lett. 2020 Aug 15;45(16):4373-4376. doi: 10.1364/OL.397882.

Abstract

Conventional coherent diffraction imaging (CDI) suffers from inherent phase retrieval ambiguity due to limited intensity-only measurements. Coded illumination with multiple modulations has been introduced to tackle the underdetermination challenge, which however slows down imaging speed. In addition, the required high-dynamic-range acquisition at the Fourier plane is also time consuming. To increase imaging speed, we report an accelerated coded CDI method in this Letter. It requires only three binarized intensity patterns to illuminate the full field, which can be implemented at ∼22kHz using a digital micromirror device. Each diffraction pattern at the Fourier plane is acquired in a single shot without high-dynamic-range synthesis, resulting in three intensity-only images corrupted with underexposed pixels. We develop an adaptive phase retrieval algorithm to adaptively remove the negative influence of underexposure and recover both the object's amplitude and phase. Both simulations and experiments validate that the method enables fast and high-fidelity complex-field imaging.