1:15 PM - 1:45 PM
[15p-413-1] Raman microscopy beyond the resolution limit
Keywords:Raman microscopy, Raman spectroscopy, Super resolution
Recent advances in the sensitivity of spectroscopic measurements drastically improve the image acquisition speed in Raman microscopy. The technological developments have created a new research field known as "analytical imaging". However, the spatial- and spectral resolutions of the Raman microscope are still limited to the level of conventional Raman microspectroscopy. In our research, we improved the spatial resolution of spontaneous Raman microscopy by applying the structured illumination technique. A sample was illuminated a line-shaped focus with an interference fringe, with which the spatial resolution for the line direction can be improved about twice without sacrificing the spectral resolution. We have confirmed the improvement of the spatial resolution by the structured line illumination in hyperspectral Raman imaging of polymer, carbon, and biological samples. We also confirmed the improvement of analytical capability in Raman imaging in these experiments. We also developed a technique to improve the spatial and spectral resolutions in coherent anti-Stokes Raman scattering (CARS) microscopy. We utilized a saturation effect in vibrational excitation via stimulated Raman scattering to introduce highly nonlinear CARS effect. Since the saturation effect dominantly occurs at the center of laser focus with satisfying the resonant condition, both of the spatial and the spectral resolution can be improved beyond the limit due to the wave nature of light. We demonstrated the super spatial and spectral resolution imaging in the observation of diamond particles.