Fig. 4
From: Broad spiral bandwidth of orbital angular momentum interface between photon and memory
High-dimensional entanglement. a The post-selected correlated orbital-angular-momentum (OAM) matrix between Signal 1 and Signal 2 photons with OAM modes difference \(\vert \Delta l\vert\) up to 16. b The sum \(N\) of visibilities for \(2\times 2\) subspaces for calculating the high-D entanglement dimensionality witness \(W\)
