Let's say that the oscillation of a dipole polarization is given by: [tex]x(t)=u\cos\omega t - \nu\cos\omega [/tex]. The driving field is given by [tex]E(t) = E\cos\omega t[/tex]. (u and nu are the in-phase and out-of-phase components, respectively)(adsbygoogle = window.adsbygoogle || []).push({});

So, the time average power is [tex]P_{avg} = \frac{1}{2}eE\omega\nu[/tex]

and the number of photons absorbed per unit time is [tex]N_{avg} = \frac{eE}{\hbar}\nu[/tex]

I'm just stuck conceptually. If I calculate directly and divide the time averaged power by the energy of a photon, I still have the constant of 1/2.

Is this dipole absorbing two photons per cycle because each photon is capable of only displacing the dipole to a maximum once, so the subsequent photon displaces it to the opposite maximum? In other words, the work is done to displace the dipole 2 separate times, once from the center to the righthand max and a second time from rest to the lefthand max? I'm getting this because the work completes 2 cycles in the time that it takes the polarization to complete 1.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Dipole Oscillation

Can you offer guidance or do you also need help?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**