This paper considers various channels of γ-quantum generation via an ultra-short high-power laser pulse interaction with different targets. We analyze the possibilities to create a pulsed γ-radiation source using laser triggering of some nuclear reactions and isomer targets. It is shown that 0.2 MeV monochromatic short pulse of γ-radiation can be obtained with pulse energy sub-mJ level from isomer atoms localized in a magnetic trap. For nuclear reaction channel in light-atom materials, it is shown that 100-TW laser pulse gives rise to formation of about 10⁶ γ-photons near 5 MeV energy.