# How to calculate angular momentum per second for a photon?

1. Oct 24, 2013

### Ishida52134

1. The problem statement, all variables and given/known data
Given a photon polarization state lphi> = lx> 3/5 + ly> 4i/5 , a beam of photons transmit N photons per second in such a state. An L-polarized photon has an angular momentum hbar along its direction of motion, and an R-polarized photon has an angular momentum of the same magnitude but opposite to direction of motion. If the beam described by the particular polarization state phi above is totally absorbed by a surface, what angular momentum is added to the surface per second on the average?

2. Relevant equations

3. The attempt at a solution
So, I know the total angular momentum is Nhbar. I'm not sure if I have to calculate the direction perpendicular to the surface or the full angular momentum which would be Nhbar.

2. Oct 25, 2013

### Simon Bridge

The beam is "totally absorbed" ... how does a beam transfer angular momentum to a surface?