Abstract Quantitative phase imaging (QPI) with its high-contrast images of optical delay (OPD) maps is often used for label-free single-cell analysis. Contrary to other methods, sensitivity improvement has not been intensively explored because conventional QPI sensitive enough observe the surface roughness a substrate that restricts minimum measurable OPD. However, emerging techniques utilize, example, differential image analysis consecutive temporal frames, such as mid-infrared photothermal...

Label-free optical imaging is valuable in biology and medicine because of its non-destructive nature. Quantitative phase (QPI) molecular vibrational (MVI) are the two most successful label-free methods, providing morphological biochemical information, respectively. These techniques have enabled numerous applications as they matured over past few decades; however, their contrasts inherently complementary difficult to integrate due reliance on different light–matter interactions. Here we...

Advancement in mid-infrared (MIR) technology has led to promising biomedical applications of MIR spectroscopy, such as liquid biopsy or breath diagnosis. On the contrary, microscopy been rarely used for live biological samples an aqueous environment due lack spatial resolution and large water absorption background. Recently, photothermal (MIP) imaging proven be applicable 2D 3D single-cell with high inherited from visible light. However, maximum measurement rate limited several frames s-1,...

Abstract An optical microscope enables image-based findings and diagnosis on microscopic targets, which is indispensable in many scientific, industrial medical settings. A standard benchtop platform, equipped with e.g., bright-field phase-contrast modes, of importance convenience for various users because the wide-field label-free properties allow morphological imaging without need specific sample preparation. However, these microscopes never have capability acquiring molecular contrast a...

Quantitative phase imaging (QPI) quantifies the sample-specific optical-phase-delay enabling objective studies of optically-transparent specimens such as biological samples, but lacks chemical sensitivity limiting its application to morphology-based diagnosis. We present wide-field molecular-vibrational microscopy realized in framework QPI utilizing mid-infrared photothermal effect. Our technique provides spectroscopic performance comparable that a conventional infrared spectrometer...

Zernike's phase contrast microscopy (PCM) is among the most widely used techniques for observing objects, but it lacks quantitative nature, as cannot directly provide information. Current methods computationally extracting distributions from PCM images, however, rely heavily on empirical regularization parameter tuning. In this paper we extend an existing approach by employing untrained neural network image prior, removing need manual regularization. We quantitatively demonstrate improved...

Vibrational microscopy provides label-free, bond-selective chemical contrast by detecting molecular vibrations, making it invaluable for biomedical research. While conventional methods rely on the direct detection of Raman scattering or infrared absorption, recently developed vibrational photothermal (ViP) achieves indirectly through refractive index (RI) changes. This indirect approach enables unique imaging capabilities beyond traditional imaging. Here, we introduce a novel application ViP...

Quantitative phase imaging (QPI), such as digital holography, is considered a promising tool in the field of life science due to its noninvasive and quantitative visualization capabilities without need for fluorescence labeling. However, popularity QPI systems limited cost complexity their hardware. In contrast, Zernike phase-contrast microscopy (ZPM) has been widely used practical scenarios but not categorized QPI, owing halo shade-off artifacts weak condition. Here, we present single-image...

Quantitative phase microscopy (QPM) literally images the quantitative shift associated with image contrast, where can be altered by laser heating. In this study, thermal conductivity and thermo-optic coefficient (TOC) of a transparent substrate are simultaneously determined measuring difference induced an external heating using QPM setup. The substrates coated 50-nm-thick titanium nitride film to photothermally generate heat. Then, is semi-analytically modeled based on heat transfer effect...

Quantitative phase microscopy (QPM), which quantifies the complex amplitude of forward-scattered (FS) light induced by specimens, enables visualization macroscopic refractive index distribution in transparent samples and has been used for various applications such as dry mass analysis cell cycle estimation. Conversely, interferometric scattering (iSCAT), captures backward-scattered (BS) light, offers higher sensitivity compared to QPM can effectively detect nanoparticles individual proteins...

Fluorescent nanothermometry has revealed pronounced inhomogeneous temperature distributions within cells and opened the field of single-cell thermal biology. However, this finding sparked a controversial discussion known as 10^5 gap issue, which arises from simple heat conduction calculation suggesting such large should not exist inside cells. This debate led to hypothesis that intracellular is considerably slower than in water. Although various efforts have been made measure conduction,...

In optical microscopy, Zernike phase-contrast microscopy (PCM) is a technique that transforms phase shifts in sample to contrast intensity by interference. Despite its wide usage many biological and clinical applications, it fails provide quantitative information about the specimen. One prior collaborative work [1] from our group managed add quantitativeness PCM retrieval algorithm based on compressive propagation. However, this relies heavily regularization non-trivial optimization tricks,...

Acquisition of molecular information is useful in various aspects science, industry and medicine. Fluorescence imaging the most widely used technique biological fields, but accompanied by chemical alteration photodamage to sample due use fluorescent labelling agents. Alternatively, label-free molecular-vibrational methods, such as mid-infrared (MIR) absorption spontaneous/coherent Raman scattering (RS) [1], suffer from low spatial resolution, sensitivity (low speed), high and/or need...

Label-free optical imaging is valuable in biology and medicine with its non-destructive property reduced chemical damages. Quantitative phase (QPI) molecular vibrational (MVI) are the two most successful label-free methods, providing morphology biochemistry, respectively, that have pioneered numerous applications along their independent technological maturity over past few decades. However, distinct contrasts inherently complementary difficult to integrate due use of different light-matter...

Advancement in mid-infrared (MIR) technology has led to promising biomedical applications of MIR spectroscopy, such as liquid biopsy or breath diagnosis. On the contrary, microscopy been rarely used for live biological samples an aqueous environment due lack spatial resolution and large water absorption background. Recently, photothermal (MIP) imaging proven be applicable 2D 3D single-cell with high inherited from visible light. However, maximum measurement rate limited several frames/s,...

We develop a coaxial time-resolved digital holographic imaging system with diffraction-grating-based common-path shearing interferometer for measuring laser ablation dynamics. The system's detectable minimum optical phase delay and spatial resolution are 1.0 mrad 690 nm, respectively. This sensitive could allow one to visualize not only the electronic response but also thermal of materials under strong excitation.

Label-free optical imaging is valuable for studying fragile biological phenomena where chemical and/or damages associated with exogenous labelling of biomolecules are not wanted. Molecular vibrational (MVI) and quantitative phase (QPI) the two most-established label-free methods that provide biochemical morphological information sample, respectively. While these have pioneered numerous important analyses along their intensive technological development over past twenty years, inherent...

We present a single-image numerical phase retrieval method for Zernike phase-contrast microscopy (ZPM) that addresses halo and shade-off artifacts, as well the weak condition, without requiring hardware modifications. By employing rigorous physical model of ZPM gradient descent algorithm its inversion, we achieve quantitative imaging. Our approach is experimentally validated using biological cells nature confirmed through comparisons with digital holography observations.