STED microscopy involves two lasers: an excitation laser and a STED laser. The excitation laser illuminates the sample, causing fluorophores to emit light. The STED laser, which is donut-shaped, depletes the fluorescence in the periphery of the excitation spot through stimulated emission. This results in a smaller effective fluorescence area, thereby increasing the resolution. The process relies on the precise alignment and timing of these lasers to achieve the desired super-resolution effect.
