Open AccessHighly sensitive lens-free fluorescence imaging device enabled by a complementary combination of interference and absorption filters
Author(s) -
Kiyotaka Sasagawa,
A. Kimura,
Makito Haruta,
Toshihiko Noda,
Takashi Tokuda
Publication year - 2018
Publication title -
biomedical optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.362
H-Index - 86
ISSN - 2156-7085
DOI - 10.1364/boe.9.004329
Subject(s) - optics , materials science , lens (geology) , interference filter , absorption (acoustics) , interference (communication) , fluorescence lifetime imaging microscopy , filter (signal processing) , fluorescence , wavelength , optoelectronics , optical filter , physics , computer science , telecommunications , channel (broadcasting) , computer vision
We report a lens-free fluorescence imaging device using a composite filter composed of an interference filter and an absorption filter, each applied to one side of a fiber optic plate (FOP). The transmission of angled excitation light through the interference filter is absorbed by the absorption filter. The auto-fluorescence of the absorption filter is reduced by the reflection from the interference filter of normally incident excitation light. As a result, high-performance rejection of excitation light is achieved in a lens-free device. The FOP provides a flat, hard imaging device surface that does not degrade the spatial resolution. We demonstrate excitation rejection of approximately 10 8 :1 at a wavelength of 450 nm in a fabricated lens-free device. The resolution of fluorescence imaging is approximately 12 µ m. Time-lapse imaging of cells containing green fluorescent protein was performed in a 5- µ m thin-film chamber. The small dimensions of the device allow observation of cell culturing in a CO 2 incubator. We also demonstrate that the proposed lens-free filter is compatible with super-resolution bright-field imaging techniques. These features open a way to develop a high-performance, dual-mode, lens-free imaging device that is expected to be a powerful tool for many applications, such as imaging of labeled cells and point-of-care assay.