Superradiant generation of femtosecond pulses in quantum-well heterostructures

We propose a new type of accessible source of ultra-short pulses based on the phenomenon of collective coherent recombination (superradiance) of electrons and holes in semiconductor heterostructures. We find and analyse a novel regime of ultra-fast operation of quantum-well semiconductor lasers in which a quasiperiodic sequence of femtosecond superradiant pulses is emitted under continuous pumping. According to our calculations for AlGaAs - GaAs heterostructures, the coherent optical pulses of duration 30 fs and peak intensity can be generated in a low- Q cavity of length .