title: FPscope: a field-portable high-resolution microscope using a cellphone lens.
abstract: The large consumer market has made cellphone lens modules available at low-cost and in high-quality. In a conventional cellphone camera, the lens module is used to demagnify the scene onto the image plane of the camera, where image sensor is located. In this work, we report a 3D-printed high-resolution Fourier ptychographic microscope, termed FPscope, which uses a cellphone lens in a reverse manner. In our platform, we replace the image sensor with sample specimens, and use the cellphone lens to project the magnified image to the detector. To supersede the diffraction limit of the lens module, we use an LED array to illuminate the sample from different incident angles and synthesize the acquired images using the Fourier ptychographic algorithm. As a demonstration, we use the reported platform to acquire high-resolution images of resolution target and biological specimens, with a maximum synthetic numerical aperture (NA) of 0.5. We also show that, the depth-of-focus of the reported platform is about 0.1 mm, orders of magnitude longer than that of a conventional microscope objective with a similar NA. The reported platform may enable healthcare accesses in low-resource settings. It can also be used to demonstrate the concept of computational optics for educational purposes.
authors.affiliation: Biomedical Engineering, University of Connecticut, Storrs, CT, 06269, USA ; These authors contributed equally to this work.
authors.forename: Siyuan
authors.initials: S
authors.lastname: Dong
authors.affiliation: Biomedical Engineering, University of Connecticut, Storrs, CT, 06269, USA ; These authors contributed equally to this work.
authors.forename: Kaikai
authors.initials: K
authors.lastname: Guo
authors.affiliation: Biomedical Engineering, University of Connecticut, Storrs, CT, 06269, USA.
authors.forename: Pariksheet
authors.initials: P
authors.lastname: Nanda
authors.affiliation: Biomedical Engineering, University of Connecticut, Storrs, CT, 06269, USA.
authors.forename: Radhika
authors.initials: R
authors.lastname: Shiradkar
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: (110.0180) Microscopy; (170.3010) Image reconstruction techniques; (170.3880) Medical and biological imaging