High-quality multi-wavelength lensfree microscopy based on nonlinear optimization

• Published in: Optics and lasers in engineering 2021-02, Vol.137, p.106402, Article 106402
• Main Authors: Guo, Cheng, Zhang, Feilong, Geng, Yong, Kan, Xingchi, Tan, Jiubin, Liu, Shutian, Liu, Zhengjun
• Format: Article
• Language: English
• Subjects: Computational imaging; Image reconstruction techniques; Phase retrieval
• ISSN: 0143-8166; 1873-0302
• DOI: 10.1016/j.optlaseng.2020.106402

•A white LED and three ultra-narrow spectral filters (FWHM=1±0.2 nm) is used to form a multi-wavelength lensfree microscope.•A multi-wavelength phase retrieval algorithm based on total variation prior is proposed to improve the imaging quality and enhance the signal-to-noise ratio.•The experimental results of resolution target, stained human goblet cell, and label-free microglia cell demonstrate the superiority of our method. In multi-wavelength lensfree microscopy (MWLM), a laser source is usually replaced with a light-emitting diode for a low-cost and portable configuration. However, the trade-off between noise suppression and resolution enhancement puts a challenging issue for high-quality imaging. Here we propose a noise-robust multi-wavelength phase retrieval to increase the stability of MWLM. To solve the inverse problem of phase retrieval, we derive an optimization procedure to iteratively minimize the data fidelity and impose a total variation term for noise suppression. The experimental results of resolution target, stained human goblet cell, and label-free microglia cell demonstrate that our method could hold a better noise tolerance without the loss of imaging resolution. We believe that our method will become a powerful tool for a resources-limited scene.