Hi

I have a simple question

What are the quantum number needed to completly describe a photon ?

Can we assing a vector to the direction of a free photon (a photon not yet detected) ?

The one I know are the frequency, the momentum (not sure they are quantum number)

Thanks

The k vector determines energy, momentum and frequency. In some kind of confined system, these would be determined by the allowed energy states, so you'd have a quantum number telling you the mode of the cavity. You have to specify the polarization, if the orthogonal states are allowed by the boundary conditions. Photons are spin 1, and can have spin projections of +1 or -1.

Thanks for your answer.

What is the k vector ?

Energy depend on the frequency

momentum depend on the energy

So only the frequency is necessary to describe energy and momentum ???

You lost me with "mode of the cavity" What cavity are talking about ?

Is polarization related to spin ?

What is "spin projection"

Is angular momentum the same thing as spin ?

Thanks again for your time.