Fig. 2

Instrumentation advances toward pushing the physical limits of CRS microscopy. a Ultra-broadband hyperspectral CARS imaging of Caenorhabditis elegans. CARS spectra from five different lipid particle regions are shown in the 600–3100 cm⁻¹ spectral region. Scale bar, 10 μm. b Video-rate 4-color SRS imaging of Euglena gracillis. Chemical maps of lipids, paramylon, chlorophyll and protein + nucleic acid are generated. Scale bar, 10 μm. c Multiplex SRS and its application to flow cytometry. A spectrum-time window SRS flow data in 1.8 ms showed 8 PMMA and 5 PS beads. SL slit, G Grating, Cyl cylindrical lens, M mirror. TAMP tuned amplifier. PD photodiode. d Ultrafast stimulated Raman scattering microscopy based on collinear multiple beams. Top inset: AOD input waveform to generate laser combs. Bottom inset, AOD diffraction angles and images of the 46-channel laser combs for both beams. Selected frames from 2-kHz label-free imaging of the polymerization process at 3043 cm⁻¹ are shown. Scale bar, 5 μm. AOD acousto-optic deflector, RF radio frequency; TD time domain, FD frequency domain; PA photodiode array, F filter. a–d are adapted from references [30], [33], [39] and [41], respectively