Fig. 4
From: Underwater transmission of high-dimensional twisted photons over 55 meters
Propagation dynamics of high-order vortices. a. Measured modal structures of high-order pure states. The red circles mark the unit-strength vortices split from a high-order vortex core. b. The evolution of the positions of three vortex cores over time for ℓ=−3 pure state. The projection cloud for OAM −3 state at the time=0 at the x-y plane marked with a yellow circle. The label X and Y axis represent the absolute position, so there are no units. c. The evolution of the inter-core distance (Δr: pixel in ICCD) for ℓ=−3 pure state