No mention of how this works..
It's called "birefringence":
> The recently developed 5D optical storage technique uses birefringence as an extra degree of freedom – the property of a medium whereby its refractive index varies depending on the polarization and direction of incident light. Birefringence generated by the orientation and size of optical nano-gratings offers two extra dimensions, providing much higher storage capacities.
Any information on how much it cost to do this? There’s also no mention of how the data is being read, at least not by this source.