Photon  Orbital  Angular  Momentum  

h0p://www.physics.gla.ac.uk/Op<cs/play/photonOAM/  

“Orbital” Angular Momentum of Photons  • Donut modes- Laguerre-Gaussian • Phase SINGULARITY

• Quantized in multiples of

|-1⟩ = L

|0⟩ = G

|1⟩ = R

!

Holographic Preparation/Detection

•  Couple into single-mode fiber -- only accepts Gaussian mode; all others too big and cannot propagate inside fiber

•  Together with the hologram we can detect other spatial modes

ℓ  

ℓ–2  ℓ–1  ℓ  ℓ+1  ℓ+2  

Diffraction at a dislocation changes the donut mode angular momentum

Qutrits!

AOM  Mode  Sorter  

!

Observa(on  of  Four-­‐Photon  Orbital  Angular  Momentum  Entanglement  B. C.  Hiesmayr,  M. J. A.  de  Dood,  and  W.  Löffler  Phys.  Rev.  LeI.  116,  073601  (2016)  Published  February  16,  2016  

TODAY!!!!