  High-precise calculation of near-infrared absorption and transient spectra in
bulk semiconductors irradiated by an intense terahertz (THz) laser shows that,
the ionization rate of the ground-state exciton, probed through the dynamic
Fano resonance, may decrease with the increase of the THz laser intensity. This
counterintuitive effect indicates the excitons are stabilized against the
field-ionization. The much lower Rydberg energy and ``atomic unit'' of laser
intensity for excitons, and the possibility of creating excitons from the
``vacuum state'' allow observing the excitonic stabilization in experiments, in
contrast to the case of atomic stabilization.
