2017/01/23 by Guangyuan Zhao, Zhao, Guangyuan, Mohammad M Kabir +14
Biochemistry, Genetics and Molecular Biology · Engineering · Neuroscience · Physics and Astronomy · #Advanced Fluorescence Microscopy Techniques #Biological Physics (physics.bio-ph) #FOS: Physical sciences #Optics (physics.optics) #Photonic and Optical Devices #Photoreceptor and optogenetics research #physics.bio-ph #physics.optics
paper · pdf · doi:10.48550/arxiv.1701.06358
5 figures
arxiv created 2017/01/23 · openalex publication_date 2017/01/23 · arxiv updated 2017/01/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We introduce the concept of saturated absorption competition (SAC) microscopy as a means of providing sub-diffraction spatial resolution in fluorescence imaging. Unlike the post-competition process between stimulated and spontaneous emission that is used in stimulated emission depletion (STED) microscopy, SAC microscopy breaks the diffraction limit by emphasizing a pre-competition process that occurs in the fluorescence absorption stage in a manner that shares similarities with ground-state depletion (GSD) microscopy. Moreover, unlike both STED and GSD microscopy, SAC microscopy offers a reduction in complexity and cost by utilizing only a single continuous-wave laser diode and an illumination intensity that is ~ 20x smaller than that used in STED. Our approach can be physically implemented in a confocal microscope by dividing the input laser source into a time-modulated primary excitation beam and a doughnut-shaped saturation beam, and subsequently employing a homodyne detection scheme to select the modulated fluorescence signal. Herein, we provide both a physico-chemical model of SAC and experimentally demonstrate by way of a proof-of-concept experiment a transverse spatial resolution of ~lambda/6.