Fig. 3: Experimental realization of optical vortex switching.

a–c Temporal traces of photoluminescence emitted from the polariton condensate, resolved into orbital angular momentum (OAM) components denoted as charge m. The same normalization is used for all data points. At small times for a–c only the ring-shaped off-resonant CW beam is on. In this case the signal is dominated by the m = +1 OAM component, emitted from a  +1 vortex mode inside the condensate. At t = 0 ps a short 120 fs off-resonant control pulse with increasing power from a to c perturbs the free evolution of the vortex. After perturbation with a 1 mW control pulse in a, the condensate returns to the original  +1 vortex state, that is, no vortex switching occurs. In b, for slightly increased control power of 4 mW, the vorticity in the condensate is switched to the  −1 mode after the pulse has passed. In c, for further elevated control power of 20 mW, the vortex switching does not occur and the condensate returns to the  +1 mode as in a. d–f 1D profiles corresponding to a–c, respectively, selected at different times. The thick black lines are at t = −500 ps (before switching pulse application) and the thin pink lines are at t = 1500 ps (after switching pulse application).