Interactive zoom display in smartphone-based digital holographic microscope for 3D imaging

• Yuki Nagahama
• received 06/17/2024; accepted 07/29/2024; posted 07/29/2024; Doc. ID 532972
• Abstract: Digital holography has applications in bio-imagingbecause it can simultaneously obtain the amplitude andphase information of a microscopic sample in a singleshot, thus facilitating non-contact, noninvasiveobservation of the 3D shape of transparent objects (phaseobjects, which can be mapped with the phaseinformation,) and moving objects. The combination ofdigital holography and microscopy is called digitalholographic microscopy (DHM). In this study, we proposea smartphone-based DHM system for 3D imaging that iscompact, inexpensive, and capable of observing objects inreal time; this system includes an optical systemcomprising a 3D printer using commercially availableimage sensors and semiconductor lasers; further, anAndroid-based application is used to reconstruct theholograms acquired by this optical system, thus outliningthe amplitude and phase information of the observedobject. Also, by utilizing scalable diffraction calculationmethods and touchscreen interaction, we implementedzoom functionality through pinch-in gestures. The studyresults showed that the DHM system successfully obtainedthe amplitude and phase information of the observedobject via the acquired holograms in an almost real timemanner. Thus, this study showed that it is possible toconstruct a low cost and compact DHM system thatincludes a 3D printer to construct the optical system anda smartphone application to reconstruct the holograms.Furthermore, this smartphone-based DHM system'sability to capture, reconstruct, and display holograms inreal time demonstrates its superiority and novelty overexisting systems. This system is also expected tocontribute to biology fieldwork and pathologicaldiagnosis in remote areas.