Fast STED microscopy with continuous wave fiber lasers

We report on fast beam-scanning stimulated-emission-depletion (STED) microscopy in the visible range using for resolution enhancement compact, low cost and turn-key continuous wave (CW) fiber lasers emitting at 592 nm. Spatial resolutions of 35 to 65 nm in the focal plane are shown for various samples including fluorescent nanoparticles, immuno-stained cells with a non-exhaustive selection of 5 commonly used organic fluorescent markers, and living cells expressing the yellow fluorescent protein Citrine. The potential of the straightforward combination of CW-STED and fast beam scanning is illustrated in a movie of the endoplasmic reticulum (ER) of a living cell, composed of 100 frames (6 mu m x 12 mu m), each of them acquired in a time shorter than 0.2 s.