Table 1.

Comparison of different postprocessing techniques in the context of CW-STED microscopy.

	CW-STED	gCW-STED	gCW-STED filt.	MID CW-STED	SPLIT CW-STED
Principle	PSF shrinking by stimulated emission depletion	PSF shrinking by stimulated emission depletion and time-gating detection	PSF shrinking by stimulated emission depletion and time-gating detection; filtering for background removal	PSF shrinking by stimulated emission depletion and MID (background is taken into account and removed)	PSF shrinking by stimulated emission depletion and SPLIT (background is estimated and removed)
Lateral resolution	20 to 50 nm3	$\sim 42\mathrm{nm}$17	$\sim 60\mathrm{nm}$20	$\sim 60\mathrm{nm}$35	$\sim 60\mathrm{nm}$24
Speed	High	High	High	Middle	Middle
Power required for the sample (mW)	$\sim 600$	$\sim 200$	$\sim 50$	$\sim 40$	$\sim 40$
Advantages	Simplicity and cost	Enhanced on–off contrast using moderate light intensities	Enhanced on–off contrast using moderate light intensities	Enhanced SNR	Enhanced SNR
Drawbacks	High photobleaching	Low SNR may negate benefit	Low SNR may negate benefit	Complex data processing with possible artifacts	Complex data processing with possible artifacts