Stable vector solitons composed of bright and dark pulses

The vector optical solitons composed of bright and dark pulses are analyzed. It is shown that in the small-amplitude limit a bound state of these solitons is described by the generalized Zakharov system, which supports coupled soliton solutions, and under special conditions it reduces to an integrable model. In the limit in which the integrable model approximation is valid, numerical simulations show rather stable bound states of bright and dark pulses as well as their almost elastic collision.