Background-Suppressed High-Throughput Mid-Infrared Photothermal Microscopy via Pupil Engineering.

ABSTRACT: Mid-infrared photothermal (MIP) microscopy has been a promising label-free chemical imaging technique for functional characterization of specimens owing to its enhanced spatial resolution and high specificity. Recently developed wide-field MIP imaging modalities have drastically improved speed and enabled high-throughput imaging of micron-scale subjects. However, the weakly scattered signal from subwavelength particles becomes indistinguishable from the shot-noise as a consequence of the strong background light, leading to limited sensitivity. Here, we demonstrate background-suppressed chemical fingerprinting at a single nanoparticle level by selectively attenuating the reflected light through pupil engineering in the collection path. Our technique provides over 3 orders of magnitude backg

SUBMITTER: Zong H 

PROVIDER: S-EPMC9373987 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature