Fig. 1: The analogue universe.
From: Analogue cosmological particle creation in an ultracold quantum fluid of light
a The fluid of light (red) is a laser pulse traversing a heated 85Rb vapor cell. The axial position gives the effective time τ. The quenches occur at the entrance and exit of the vapor cell. τ = 0 corresponds to quench 2. The time between the two quenches is τ12. b The true time gives an effective third spatial dimension z′. c Typical image of the fluid of light integrated along z′, given in units of photon density. An effective time τ = 103 ps after quench 2 is shown.
