Lasing state hysteresis in a two-state quantum dot laser via optical injection

Abstract

Quantum dot lasers readily lase from multiple distinct energy states. We examine the influence of optical injection into the ground state (GS) when the free-running operation is the first second excited state (ES) only and demonstrate the existence of an injection-induced bistability between GS emission and ES emission. There is a consequent hysteresis loop in the lasing output. Experimental and numerical investigations are in excellent agreement.