[orgstudy]

Which compound can be used to produce LASER. I mean the compound (or element) has a very stable "metastable state" and is also feasible!!!

Thanks!!

[Enthalpy]

Many many ones would!

But then, you also need a process to bring >50% of you lasing centres in the excited state. This needs some invention, and the material used is completely coupled with the usable pumping method.

You may also want your laser to survive when its lasing centres are 1eV above ground state, which is likely to evaporate a plain solid. So the lasing centres may be a dopant hold in a glass matrix, a gas, electrons in the conduction band of a semiconductor...

If you like chemistry, you may consider the oxygen molecule in its singlet state. Used in the COIL laser.

Wikipedia maybe?