  In this paper, we investigate the deuterium-tritium (DT) fusion process in
the presence of strong laser fields with a semiclassical (SC) method. In this
model, two nuclei with a given incident kinetic energy that closely approach
each other are simulated by tracing the classical Newtonian trajectories in the
combined Coulomb repulsive potentials and laser fields. At the nearest position
or classical turning point, quantum tunneling through the Coulomb barrier
emerges, and its penetrability is estimated with the Wentzel-Kramers-Brillouin
formula. Nuclear fusion occurs after the tunneling, and the total fusion cross
section takes the Gamow form. We find that the tunneling penetrability can be
enhanced dramatically because the nuclei can closely approach each other due to
the quiver motion of the charged nuclei driven by the intense laser fields. We
then calculate the DT fusion section for a wide range of laser parameters
according to various incident nuclei kinetic energies and obtain the phase
diagrams for the enhanced DT fusion. We compare our SC results with the quantum
results of the Kramers-Henneberger approximation and the Volkov state
approximation.
