Abstract
We demonstrated that optical subcycle pulses can be generated in dense media of two-level systems due to pulse splitting and reshaping of pulses of a few optical-cycles time duration. Novel features in the spectral signatures of the pulses are predicted, a large blueshift in the transmitted and a large redshift in the reflected pulse, which are explained by intrapulse four-wave mixing. Solitary propagation phenomena in the full Maxwell-Bloch equations beyond the limits of slowly varying envelope and rotating-wave approximations are observed, e.g., the formation of solitary half-cycle pulses and two-soliton pulses.