Fig. 1. Experimental setup. M1–4: mirrors; 850SP: short-pass filter cutting off at 850 nm; GP1, 2: Glan prisms; HWP1–3: half-waveplates; DM1: dichroic mirror reflecting the laser of 532 nm and passing the fluorescence longer than 580 nm; DM2: dichroic mirror reflecting the laser of 1064 nm and passing the fluorescence shorter than 980 nm; 1064LP: long-pass filter cutting off at 1064 nm; Obj: microscope objective lens; S: sample; L1–4: focusing lenses; PH: pinhole; 545LP: long-pass filter cutting off at 545 nm; PBS: polarized beam splitter; FM: flip mirror; APD1, 2: Si-avalanche photodiode single-photon detectors; TCSPC: time-correlated single-photon counter.

Fig. 2. (a) PL scan image in x×y dimension of the SPE when excited by the green laser. Inset: suppressed PL scan image of the SPE in the same region by adding the NIR laser. Note that the two images share the same intensity color bar. (b) PL spectra of the SPE pumped with only the green laser, with additional low-power NIR laser, and with high-power NIR laser. Inset: SPE PL photon-correlation. (c) Excitation polarization, emission polarization, and suppression polarization; (d) SPE PL intensity under simultaneous green and NIR excitations as a function of both green and NIR laser powers.

Fig. 3. (a) Evolution of the PL emission lifetime as a function of the delay between the green and the NIR laser pulses; (b) concept diagram of energy levels of an optical switch based on the SPE in 3C-SiC.

Fig. 4. Deconvolution of the PL response to the NIR laser pulse when pumped with a continuous-wave green laser, and fitting curves of rising and falling edges by the single exponential function. The inset is a schematic of the corresponding pulse sequence.

Fig. 5. (a) PL scan image in x×y dimension excited with only the green pulsed laser; (b) intensity profile along the dashed line in (a); (c) STED PL scan image in x×y dimension by adding the NIR laser donut depletion beam; (d) intensity profile along the dashed line in (c); (e) STED microscope resolution as a function of the NIR power. Error bars indicate the standard deviation in the Gaussian fitting.