With its electrons round the atoms
Circling, as if in a trance
Oscillating in their dance.
And then, if you disturb the system,
A signal to inject insist, then
An electron jumps its shell
And wrecks the balance all to hell,
And loses energy, engagement;
A photon leaves the whole arrangement.
And when this happens more and more
And photons radiate galore,
You have a laser shining bright
With red, or orange, or green light...