  We present hitherto unknown forms of soliton dynamics in the forbidden
frequency gap of a Bragg reflector, modified by periodic layers of
near-resonant two-level systems (TLS). Remarkably, even extremely low TLS
densities create an allowed band within the forbidden gap. This spectrum gives
rise, for any Bragg reflectivity, to a vast family of stable gap solitons, both
standing and moving, having a unique analytic form, an arbitrary pulse area,
and inelastic collision properties. These findings suggest new possibilities of
transmission control, noise filtering or ``dynamical cavities'' (self-traps)
for both weak and strong signal pulses.
