Invited Article: Mask-modulated lensless imaging with multi-angle illuminations

Autor: Zibang Zhang, You Zhou, Shaowei Jiang, Kaikai Guo, Kazunori Hoshino, Jingang Zhong, Jinli Suo, Qionghai Dai, Guoan Zheng
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: APL Photonics, Vol 3, Iss 6, Pp 060803-060803-12 (2018)
Druh dokumentu: article
ISSN: 2378-0967
DOI: 10.1063/1.5026226
Popis: The use of multiple diverse measurements can make lensless phase retrieval more robust. Conventional diversity functions include aperture diversity, wavelength diversity, translational diversity, and defocus diversity. Here we discuss a lensless imaging scheme that employs multiple spherical-wave illuminations from a light-emitting diode array as diversity functions. In this scheme, we place a binary mask between the sample and the detector for imposing support constraints for the phase retrieval process. This support constraint enforces the light field to be zero at certain locations and is similar to the aperture constraint in Fourier ptychographic microscopy. We use a self-calibration algorithm to correct the misalignment of the binary mask. The efficacy of the proposed scheme is first demonstrated by simulations where we evaluate the reconstruction quality using mean square error and structural similarity index. The scheme is then experimentally tested by recovering images of a resolution target and biological samples. The proposed scheme may provide new insights for developing compact and large field-of-view lensless imaging platforms. The use of the binary mask can also be combined with other diversity functions for better constraining the phase retrieval solution space. We provide the open-source implementation code for the broad research community.
Databáze: Directory of Open Access Journals