  Periodically driven systems provide tunable platforms to realize interesting
Floquet topological phases and phase transitions. In electronic systems with
Weyl dispersions, the band crossings are topologically protected even in the
presence of time-periodic perturbations. This robustness permits various routes
to shift and tilt the Weyl spectra in the momentum and energy space using
circularly polarized light of sufficient intensity. We show that type-II Weyl
fermions, in which the Weyl dispersions are tilted with the appearance of
pocket-like Fermi surfaces, can be induced in driven Dirac semimetals and line
node semimetals. Under a circularly polarized drive, both semimemtal systems
immediately generate Weyl node pairs whose types can be further controlled by
the driving amplitude and direction. The resultant phase diagrams demonstrate
experimental feasibilities.
