# Can stimulated emission happen in nuclear energy states? [duplicate]

We know that stimulated emission of photons can occur when photons induce an electron in a metastable state to drop down, creating a new photon which is identical to the original photon in terms of frequency, phase, and polarization.

I'm wondering, can the phenomenon of stimulated emission be extended to nuclear transitions as well? The existence of nuclear stimulated emission could mean that gamma ray lasers are possible.

• As a practical matter establishing a population inversion may be difficult in many systems (but I suppose that Tc-99m is an obvious candidate) Nov 9 '17 at 5:33
• @dmkee Is it because that metastable states are rare in nuclear states? Nov 9 '17 at 5:38
• The problem with making a laser is: how do you want to make the mirrors? Nov 9 '17 at 6:05

• That paper looks nice, but I'm not sure I fully understand it. Tkalya's scheme lases "gamma rays" at 7.6 eV $\leftrightarrow$ 160 nm? I'm not sure I'd call that XUV, let alone x-rays. (It's still a nuclear-transition laser, obviously.) Nov 9 '17 at 18:05