a, Laser pulses (40 ps FWHM) are reflected from a photonic crystal cavity that is linearly polarized at 45∘ relative to the input polarization set by the polarizing beam splitter (PBS). The output light, observed in cross-polarization and carrying the cavity-coupled signal, is analysed using an HBT set-up that measures second-order correlation. The inset shows the suspended structure with the photonic crystal cavity and the metal pad for local temperature tuning16. BS: beam splitter; QD: quantum dot; D1 and D2: single-photon detectors. b, Anticrossing observed in photoluminescence as the quantum dot is tuned into resonance with the cavity. The temperature tuning is done by linearly increasing the power (P) of the heating laser16. The right panel shows the spectrum at the anticrossing point marked by the blue line. The red lines mark the cavity and quantum-dot resonance as if they were decoupled.