Enhanced Coherent anti-Stokes Raman Scattering imaging using silica mircospheres

A technique was developed to achieve enhanced coherent anti-Stokes Raman scattering (CARS) imaging using self-assembled silica microspheres. In this study, a layer of optically transparent silica microspheres was self-assembled onto polymer grating samples to enhance the CARS signals. The highest enhancement of 12.5 was achieved using 6.1-mu m-diameter microspheres for C-H molecule vibration. Finite-difference time-domain (FDTD) algorithm under the perfectly matched layer boundary condition was used to simulate the enhancement using silica microspheres of different diameters.