High-speed coherent Raman fingerprint imaging of biological tissues

An imaging platform based on broadband coherent anti-Stokes Raman scattering has been developed that provides an advantageous combination of speed, sensitivity and spectral breadth. The system utilizes a configuration of laser sources that probes the entire biologically relevant Raman window (500-3,500 cm(-1)) with high resolution (<10 cm(-1)). It strongly and efficiently stimulates Raman transitions within the typically weak 'fingerprint' region using intrapulse three-colour excitation, and utilizes the non-resonant background to heterodyne-amplify weak Raman signals. We demonstrate highspeed chemical imaging in two- and three-dimensional views of healthy murine liver and pancreas tissues as well as interfaces between xenograft brain tumours and the surrounding healthy brain matter.