LED array position error correction in lensless optical microscopy through adaptive genetic strategy

Abstract Despite the complex optical lens system, classical optical microscopy cannot achieve high spatial resolution and a large field of view (FOV). The lensless optical ptychographic microscopy technique solves the contradiction between resolution and FOV with a simple optical path. However, position errors between LED array and sample, caused by misalignment of optical imaging axis and manufacture errors of LED array, decrease reconstruction quality. Due to the difficulty of hardware correction, we propose an adaptive genetic strategy to correct LED array position error for lensless ptychographic imaging. Firstly, the coarse positions of the LEDs are predicted by Kalman filter, thus we can determine the position range. Secondly, the precise positions of LEDs are calculated by our adaptive genetic algorithm, which combines the fitness function according to the previous predicted positions. Finally, we incorporate the LED array position correction into the Gerchberg–Saxton (GS) phase recovery method to achieve improved reconstructed image quality. Compared with similar methods, both simulation and real experiments indicate that our method genetic algorithm adapt-GS (adaptive Genetic algorithm-based GS) method has higher robustness in position errors correction, and creates results with better quality. This method is applied to other state-of-art reconstruction algorithms as a pre-processing step, highly improve the image quality.