Optical gain due to phonon-assisted exciton transitions in quantum wires

The creation of optical gain through excitonic mechanisms in quantum wires has been theoretically investigated by taking into consideration the longitudinal-optical-phonon-assisted exciton transitions. The gain values obtained are comparable to those obtained by the conventional electron-hole recombination process. Moreover, the excitonic gain is found to set in at a much lower electron-hole pair density than the gain due to the conventional process. These results strongly suggest the involvement of excitons in creating optical gain in actual quantum wires.