Figure 5.

All-optical signal modulation using photoswitchable probes. a) Fluorophores with photoswitchable dark states for super-resolution imaging: stochastic reactivation produces signals at a low density, whose positions can be mapped with subwavelength precision for reconstructive imaging. [76,78] Published with permission from the Nature Publishing Group. b) Photoswitchable fluorescent signals modulated by a periodic bleaching/recovery cycle, followed by FT demodulation for dynamic contrast enhancement. [81,82]