A multimodal platform for nonlinear optical microscopy and microspectroscopy.

Multimodal nonlinear optical microscopy is a valuable tool to study complex biological samples. We present an easy-to-operate approach to perform coherent anti-Stokes Raman scattering (CARS), two-photon fluorescence (TPF), second harmonic generation (SHG), and third-harmonic generation (THG) imaging using a single laser source composed of an 80 MHz femtosecond (fs) laser, an optical parametric oscillator (OPO), and a PPLN crystal for frequency doubling. The platform allows vibrationally resonant CARS imaging of CH-rich myelin sheath in fresh spinal tissues and lipid bodies in live cells. Multimodal nonlinear optical imaging and microspectroscopy analysis of fresh liver tissues are demonstrated.