Remember I said that when an excited molecule wants to emit it has to emit into a mode?

Often, though not always, the energy of the excited molecule is very rapidly redistributed to produce a lower energy state.

The rule is relevant in understanding the emission spectrum of an excited molecule.

However, excited molecules are frequently less capable of light emission in terms of brightness and duration when compared to sensitizers.

This is because sensitizers can store energy (that is, be excited) for longer periods of time than other excited molecules.

Hence, if an excited molecule transfers its energy to a sensitizer thus exciting it, longer and easier to quantify light emission is often observed.

The excited molecules then undergo stimulated emission in the optical resonator region of the laser.

They occur in chemical plants when a single excited molecule prompts its neighbors into a cascade of combination to create plastics.

As the excited molecules absorb the second pulse, they are further excited to even higher states.

These excited molecules have an increase in dipole momentum and in some cases can undergo internal charge rearrangement.