Figure 3: Optical setup of the multimodal/hyperspectral CARS microscopy system. A 60 fs laser beam centered at 800 nm is split into two beams, one beam becomes the pump/probe at 800 nm and the other beam generates a supercontinuum using a photonic crystal fiber. The red part of the supercontinuum (~950–1150 nm) becomes the “Stokes” beam. The two beams are chirp-matched using high dispersion SF6 glass and they are overlapped in time and space. Spectral scanning is done by overlapping the pump with different portions of the “Stokes” beam by delaying the arrival time of the pump/probe beam using a high-resolution linear stage. The two beams are sent to the microscope where high speed galvo mirrors raster-scan the beam over the sample.