High-speed broadband Fourier-transform coherent anti-stokes Raman scattering spectral microscopy

We demonstrate broadband Fourier-transform coherent anti-Stokes Raman scattering (FT-CARS) spectral microscopy with a pixel dwell time of 42 μs, which is ~50 times shorter than the shortest-to-date pixel dwell time for CARS spectral microscopy. Our broadband FT-CARS spectral microscope is composed of an FT-CARS spectrometer, a rapid galvanometric scanner, and a high-speed image acquisition circuit, enabling a frame rate of 2.4 fps with a pixel resolution of 100 × 100 pixels, a bandwidth of 600–1,200 cm⁻¹, a spatial resolution of 0.95 μm, and a spectral resolution of 37 cm⁻¹. As a proof-of-principle demonstration, we used the high-speed FT-CARS spectral microscope to perform CARS imaging of polymer beads and Haematococcus lacustris cells. Our high-speed broadband CARS spectral microscope holds promise for studying rapid cellular dynamics, such as signaling, cell-to-cell communication, and molecular transport in a label-free manner.