| In this work, we demonstrate a new method in coherent anti-Stokes Raman scattering (CARS) microscopy, which we call Focus Engineered CARS (FE-CARS). This technique opens up many options for improvement of the conventional CARS microscopy method. In particular, in our experiments we demonstrate the detection of interfaces for liquid/solid samples and an improvement of the imaging resolution in the lateral direction. Whereas the preliminary enhancement was approximately 17%, this work has laid the foundation for further resolution improvements with the FE-CARS technique. Theoretical simulations indicate that further reduction is possible. Also, we have made important steps towards miniaturization of the CARS setup for medical research. The laser pulses needed for the generation of CARS signal inside biological tissue were delivered through a long GRIN rod, which is compatible with endoscopic applications, and the resulting CARS signal was acquired in the epi-direction through the same module. Preliminary results encourage further development and improvement of the CARS endoscope technique. |
