Coherent modulation imaging quality improvement using spatial–temporal information multiplexing

Coherent diffraction imaging (CDI), as a classical lensless imaging method, can reconstruct the amplitude and retrieve the phase by diffraction intensities. Coherent modulation imaging (CMI) uses a complex modulator and therefore improves the convergence of CDI. However, the retrieval results can be seriously affected by the noise in the modulator calibration results and the captured diffraction intensity images. A CMI quality improvement using the spatial–temporal information multiplexing (STM-CMI) method is proposed, which adopts an extended coherent modulated imaging algorithm to iteratively retrieve the object information by capturing the diffraction intensity images at different time points and different spatial locations. Compared with common CMI, STM-CMI can effectively reduce noise, improve resolution, and accelerate iterative convergence. The performance of the proposed method to improve retrieved quality has been verified through simulations and experiments.