Fig. 5
Intensity cross-correlations of two coupled micropillar lasers. a Intensity cross-correlation \(g_{w_1w_2}^{(2)}(t_2 - t_1)\) of the weak modes of pillars P1 and P2. The weak modes were tuned to resonance (νw = 0) in face-to-face configuration (see configuration a in Fig. 1) at injection currents IP1 = 27.7 μA and IP2 = 24.5 μA. The two main peaks at 4.3 ns suggest leader-laggard synchronization of the intensity fluctuations between the lasers. One roundtrip (7.7 ns) further, at 12 ns, weaker revival peaks are barely observable. b, c Simulated intensity dynamics, showing the leader-laggard behavior of the two coupled micropillars P1 (panel b, upper trace: strong mode, lower trace weak mode) and P2 (panel c, upper trace: strong mode, lower trace weak mode) at injection currents of IP1 = 27.1 μA and IP2 = 24.2 μA. The time axis for pillar P2 has been shifted with respect to pillar 1 by 3.85 ns, i.e., the optical distance between the two micropillars. This illustrates the delayed correlation of the intensity fluctuations
