  We study the coupled charge-lattice dynamics in the commensurate charge
density wave (CDW) phase of the layered compound 1T-TaS$_{2}$ driven by an
ultrashort laser pulse. For describing its electronic structure, we employ a
tight-binding model of previous studies including the effects of lattice
distortion associated with the CDW order. We further add on-site Coulomb
interactions and reproduce an energy gap at the Fermi level within a mean-field
analysis. On the basis of coupled equations of motion for electrons and the
lattice distortion, we numerically study their dynamics driven by an ultrashort
laser pulse. We find that the CDW order decreases and even disappears during
the laser irradiation while the lattice distortion is almost frozen. We also
find that the lattice motion sets in on a longer time scale and causes a
further decrease in the CDW order even after the laser irradiation.
