Some people argue that out civilisation might go down for a very long time and fear that all our knowledge could be lost during some new "dark ages"

Here is a technology that claims that it can store 360TB for a very very long time:

The question remains open: How long will it take a new civilisation to have three dimensional laser technology on a micro scale to read out that data again ?
How much of complexity does this civilisation require and with what kind of surplus energy do they want to achieve this ?
As I read it a microscope and a plarisation filter is enough to read out the data ? I am not confinced, but might be possible.