title: Microscopy illumination engineering using a low-cost liquid crystal display.
abstract: Illumination engineering is critical for obtaining high-resolution, high-quality images in microscope settings. In a typical microscope, the condenser lens provides sample illumination that is uniform and free from glare. The associated condenser diaphragm can be manually adjusted to obtain the optimal illumination numerical aperture. In this paper, we report a programmable condenser lens for active illumination control. In our prototype setup, we used a $15 liquid crystal display as a transparent spatial light modulator and placed it at the back focal plane of the condenser lens. By setting different binary patterns on the display, we can actively control the illumination and the spatial coherence of the microscope platform. We demonstrated the use of such a simple scheme for multimodal imaging, including bright-field microscopy, darkfield microscopy, phase-contrast microscopy, polarization microscopy, 3D tomographic imaging, and super-resolution Fourier ptychographic imaging. The reported illumination engineering scheme is cost-effective and compatible with most existing platforms. It enables a turnkey solution with high flexibility for researchers in various communities. From the engineering point-of-view, the reported illumination scheme may also provide new insights for the development of multimodal microscopy and Fourier ptychographic imaging.
authors.affiliation: Biomedical Engineering, University of Connecticut, Storrs, CT, 06269, USA ; Equal contribution.
authors.forename: Kaikai
authors.initials: K
authors.lastname: Guo
authors.affiliation: Biomedical Engineering, University of Connecticut, Storrs, CT, 06269, USA ; Equal contribution.
authors.forename: Zichao
authors.initials: Z
authors.lastname: Bian
authors.affiliation: Biomedical Engineering, University of Connecticut, Storrs, CT, 06269, USA.
authors.forename: Siyuan
authors.initials: S
authors.lastname: Dong
authors.affiliation: Biomedical Engineering, University of Connecticut, Storrs, CT, 06269, USA.
authors.forename: Pariksheet
authors.initials: P
authors.lastname: Nanda
authors.affiliation: Institute of Materials Research and Engineering, ASTAR, 3 Research Link, 117602 Singapore.
authors.forename: Ying Min
authors.initials: YM
authors.lastname: Wang
authors.affiliation: Biomedical Engineering, University of Connecticut, Storrs, CT, 06269, USA ; Electrical and Computer Engineering, University of Connecticut, Storrs, CT, 06269, USA.
authors.forename: Guoan
authors.initials: G
authors.lastname: Zheng
keywords: (100.3190) Inverse problems; (170.0180) Microscopy; (170.2945) Illumination design; (170.3010) Image reconstruction techniques