Fig. 3: Spectral diffusion dynamics.
From: Check-probe spectroscopy of lifetime-limited emitters in bulk-grown silicon carbide
a Experimental sequence. A ‘check’ block (2 ms, 20 nW) is followed by a system perturbation (marked ‘X’), which here consists either of turning off the lasers (c), turning on the NIR lasers (d), or turning on the repump laser (e). A second block (2 ms, 20 nW) probes whether the defect has diffused away, or has ionised (denoted ‘probe’). Data is post-selected by imposing a minimum-counts threshold (T), heralding the emitter on resonance in the first (second) block and computing the mean number of counts in the second (first) block, which encodes the emitter brightness at future (past) delay times t. b Schematic illustrating the expected signal (according to Eq. (1)), when either ionisation or spectral diffusion is dominant (setting γr ≈ 0). c No significant spectral diffusion or ionisation is observed when the lasers are turned off. The solid line is a fit to the data using Eq. (1). Dashed grey line denotes the set threshold (in a 2 ms window). d Experiment and fit under 20 nW of NIR laser power (916 nm). e Experiment and fit under 1 μW of repump laser power. f Extracted saturation-diffusion rates, obtained at laser powers of ~20 nW (resonant) and ~5 μW (repump). See supplementary Fig. 3 for underlying data and error analysis.
