We study theoretically the transmission of radiation through superlattices of finite length, where the dielectric constant of one film in each unit cell contains a term linear in the local field intensity. When such a system is illuminated with radiation with frequency in a stop gap, increasing power can switch it from a state with low transmissivity to a state with transmissivity of unity. Gap solitons play a key role in the phenomenon.

• Received 29 September 1986

DOI:https://doi.org/10.1103/PhysRevLett.58.160