Fig. 1. Optical paths. (a) Optical path for Z-scan; (b) optical path for detection of fluorescence spectrum

Fig. 2. Spectrum versus time and cycle diagram of fluorescence switch. (a) Ultraviolet-visible absorption spectrum versus UV irradiation time (inset: structure of diarylethene D1); (b) fluorescence spectrum versus time; (c) fluorescence spectrum conversed by ring-opening versus time under irradiation by 375 nm laser; (d) cycle diagram of fluorescence switch under alternating irradiation by ultraviolet and visible light

Fig. 3. Test results. (a) Fluorescence spectrum conversed by ring-opening via two-photon absorption versus time (inset: fluorescence intensity contrast versus ring-opening two-photon absorption conversion power density; (b) data and fitting results from ring-opening Z-scan; (c) schematic of photon-erasing effect of diarylethene D1 in super-resolution optical storage; (d) fluorescence-quenching spectrum of diarylethene D1

Fig. 4. Calculation results of effective absorption intensity of two-photon-dual-beam and absorption intensity resolution. (a) Effective absorption intensity when inhibition ratio is 2; (b) effective absorption intensity resolution under different fluorescence intensity contrast; (c) simulated longitudinal resolution of linear energy absorption intensity; (d) simulated longitudinal resolution of effective absorption intensity; (e) simulated effective absorption intensity after threshold control; (f) eff

Fig. 5. Schematic of optical recording and reading of diarylethene D1. (a) Super-resolution; (b) original

Table 1. Conversion power density threshold of ring-opening two-photon absorption and photon energy threshold versus wavelength

Table 2. Fluorescence quenching contrast versus power density