Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Relaxation time and spatial width

  1. Jan 14, 2010 #1


    User Avatar

    Consider a two-level system, let T1 be the relaxation time for the excited system and T2 is the relaxation time for coherence. If we use a Gaussian (with small constant waist w) [tex]exp(-x^2/w^2)[/tex] to shine on the sample, because the waist is small, propably only the atoms around x=0 will be excited. Note that the excited atoms will emit lights eventually. If we collect the lights from the sample, we will get a Gaussian profile with constant waist eventually. What interesting is if we do the same thing on two medium, for one T1/T2 is small but for the other, T1/T2 is big. You will find that the waist of the emitted Gaussian spatial profile for big T1/T2 is smaller than that for small T1/T2, why's that? What's the significance for big T1 and small T2? How does this affect the waist of the emitted light?
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted