Super-resolution lensless on-chip microscopy based on array illumination and scattering multiplexing with polystyrene microspheres layer

• Published in: Optics and laser technology Vol. 181; p. 111863
• Main Authors: Li, Yulong, Lin, Zhongrui, Ma, Jianshe, Zuo, Chao, Su, Ping
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2025
• Subjects: Ptychography imaging; Scattering multiplexing; Super-resolution; Ptychography imaging; Super-resolution; Scattering multiplexing
• ISSN: 0030-3992
• DOI: 10.1016/j.optlastec.2024.111863

•An integrated pixel super-resolution lensless imaging system is developed.•The combination of array illumination and scattering layer forms diffraction diversity .•A new reconstruction algorithm has been proposed.•Breaking through the limitation of pixel size in image sensors. The resolution of lensless on-chip microscopy is mainly limited by the pixel size of the image sensor. Many super-resolution techniques have emerged to solve the problem of insufficient imaging resolution. Most existing pixel super-resolution technologies rely on precise electric translation stage for hundreds of high-precision displacements, or on expensive tunable lasers to generate diffraction diversity. Conventional ptychography iterative engine (PIE) is considered an effective method for improving imaging resolution, but it is prone to oscillations in the early stage of iteration. In this paper, we propose a ptychography imaging technique based on scattering multiplexing, which involves coating the surface of the image sensor with a layer of polystyrene microspheres, and utilizing a 4 × 3 LED array to sequentially illuminate the sample. An innovative ptychography reconstruction algorithm based on dual amplitude gradient descent (DAGD) is designed for the reconstruction from the holograms, which effectively avoids the problems of slow convergence speed and obvious oscillation. Compared with other similar technologies, our system has no moving parts and uses inexpensive partially coherent light illumination. It only records 12 holograms and reaches the imaging resolution of 1.23 μm, which is 1.36 times pixel super-resolution compared with the pixel size of the sensor.