▎ 摘　　要

Graphene's fluorescence quenching is studied as a function of distance. Transverse decay channels, full retardation, and graphene-field coupling to all orders are included, extending previous instantaneous results. For neutral graphene, a virtually exact analytical expression for the fluorescence yield is derived, valid for arbitrary distances and only based on the fine structure constant alpha, the fluorescent wavelength gimel, and distance z. Thus graphene's fluorescence quenching measurements provide a fundamental distance ruler. For doped graphene and at appropriate energies, the fluorescence yield at large distances is dominated by transverse plasmons, providing a platform for their detection.