Gain conditions for conducting polymer lasers

Abstract

The condition of lasing threshold for solid-state conducting polymers is studied using a model Hamiltonian, which includes quasi-particles corresponding to both Intrachain and interchain electronic excitations. We found that net gain can be achieved when the pump is so strong that intrachain and interchain species are mixed. A guide to overcome the difficulties coming from the photo-induced absorption due to the interchain excitations is proposed.