Abstract
Raman scatting realizes non-staining molecular imaging because of high selectivity of molecular species with molecular vibrations. However, conventional spontaneous Raman imaging requires long measurement time due to the low cross-section of Raman scattering. Coherent nonlinear Raman imaging overcomes the problem. In the presentation, our developed coherent nonlinear Raman microscopy system using a high-speed tunable and synchronized picosecond mode-locked laser is described. The combination of coherent nonlinear Raman and second harmonic generation visualizes lipid and collagen, respectively. Simultaneous imaging of lipid and collagen applies to observation of arteriosclerotic lesion of artery. A prototype of lock-in image sensor for stimulated Raman imaging, which is one of the coherent Raman imaging, is also described, and the fundamental properties of the sensor and imaging results will be shown. The lock-in image sensor enables parallel excitation and detection of stimulated Raman. At the last, the concept of coherent nonlinear Raman endoscopy will be described.
