Stimulated-emission-depletion microscopy with a multicolor stimulated-Raman-scattering light source.

We describe a subdiffraction-resolution far-field fluorescence microscope employing stimulated emission depletion (STED) with a light source consisting of a microchip laser coupled into a standard single-mode fiber, which, via stimulated Raman scattering (SRS), yields a comb-like spectrum of seven discrete peaks extending from the fundamental wavelength at 532 nm to 620 nm. Each of the spectral peaks can be used as STED light for overcoming the diffraction barrier. This SRS light source enables the simple implementation of multicolor STED and provides a spectral output with multiple available wavelengths from green to red with potential for further expansion.