Nonlocality degradation of two-mode squeezed vacuum in absorbing optical   fibers
  Transfer of nonlocal two-mode squeezed vacuum state through symmetrical and asymmetrical lossy channel is analysed and we demonstrate that the nonlocality is more robust against losses, than it has been previously suggested. It can be important for security of continuous-variable quantum cryptography employing entangled states. 
Radim Filip and L. Mista Jr