Mode des Photons identifiziert und ist mit der Lichtkraft gekoppelt.
Light possesses angular momentum which is independent of polarisation.
This angular momentum can be identified with the transversal mode and it is also related with the light force. Recently it has been assumed that the conservation of that external angular momentum plays an important role in the downconversion process . Thus the quantum number of the angular momentum is determined. The experiment can be done for any choice of orthogonal mode system, like any Hermite or Laguerre-Gaussian transversal mode. The external angular momenta of the two photons are entangled .