Skip to main content
Physics

You are not logged in. Your edit will be placed in a queue until it is peer reviewed.

We welcome edits that make the post easier to understand and more valuable for readers. Because community members review edits, please try to make the post substantially better than how you found it, for example, by fixing grammar or adding additional resources and hyperlinks.

5
  • $\begingroup$ Your answer answers my question partly. My main question is why is the polarization /phase of the emitted photon random rather than similar to the absorbed photon? $\endgroup$
    – physics2000
    Commented Mar 26, 2018 at 16:06
  • $\begingroup$ @physics2000, in spontaneous emission the first photon is absorbed and no longer exists. Then some time later (nanoseconds, microseconds, or megaseconds) a new photon is emitted. But since the old photon no longer exists, there's no way for the new photon to have any connection to it. $\endgroup$
    – The Photon
    Commented Mar 26, 2018 at 16:11
  • $\begingroup$ now this makes sense. But why does the opposite happen in stimulated emission? Thanks for the reply though. $\endgroup$
    – physics2000
    Commented Mar 26, 2018 at 16:13
  • $\begingroup$ @physics2000, stimulated emission can be looked at as a resonant phenomenon. The incoming photon stimulates a resonance in the atomic system. Like in any driven resonant system, the driven response has a (controlled) phase relationship with the driving force. $\endgroup$
    – The Photon
    Commented Mar 26, 2018 at 16:17
  • $\begingroup$ How do we calculate the lifetime of the excited state, in the case of spontaneous emission? $\endgroup$
    – Lex Lindsey
    Commented Feb 15, 2020 at 19:01