Label-free super-resolution stimulated Raman scattering imaging of biomedical specimens

Far-field super-resolution microscopy has unraveled the molecular machinery of biological systems that tolerate fluorescence labeling.Conversely, stimulated Raman scattering (SRS) microscopy provides chemically selective high-speed imaging in a label-free manner by exploiting the intrinsic vibrational properties of specimens.Even though there were various proposals for enabling far-field super-resolution Raman microscopy, the demonstration of a technique compatible with imaging opaque biological specimens has been so far elusive.Here, we demonstrate a single-pixel-based scheme, combined with robust structured illumination, that enables super-resolution in SRS microscopy.The methodology is straightforward to implement and provides label-free super-resolution imaging of thick specimens, therefore paving the way for probing complex biological systems when exogenous labeling is challenging.