STED microscopy with a MHz pulsed stimulated-Raman-scattering source.

We perform stimulated emission depletion (STED) microscopy with a novel light source consisting of a fiber-amplified, frequency doubled laser operating with a 1 MHz repetition rate and a 530 nm output coupled into a standard single mode fiber to produce a tunable spectrum of discrete peaks via stimulated Raman scattering (SRS). Using peaks at 585, 600, and 616 nm as STED light we perform STED microscopy with resolution down to 20-30 nm. The nanosecond pulsed light source should prove valuable for all forms of microscopy requiring both brilliance and multiple wavelengths in the visible range.