  Laser-induced nuclear recollisions following $\alpha$ decay in the presence
of an intense laser field are investigated theoretically. We show that while an
intense optical laser does not influence notably the tunneling rate in $\alpha$
decay, it can completely change the $\alpha$ particle spectrum. For intensities
of $10^{22}-10^{23}$ W/cm$^{2}$, the field is strong enough to induce
recollisions between the emitted $\alpha$ particle and the daughter nucleus.
The energy gained by the $\alpha$ particle in the field can reach 20 MeV and
suffice to trigger several types of nuclear reactions on a femtosecond time
scale. Similar conclusions can be drawn about laser-induced recollisions after
proton emission. Prospects for the experimental realization of laser-induced
nuclear recollisions are discussed.
