Now presumably, this 622 Mbit/sec was outbound only (Earth to Moon) and not a return trip. So that will help quite a lot.
But to get these remarkable bandwidths, the Earth-based laser and beam expander/collimator must be pretty special.
Does anyone know the juicy figures like: Laser wavelength, energy per pulse, pulse rep rate, and so on? Oh, and the strength of the signal received at the moon, in (I dunno) photons-per-bit or something?