Gain narrowing and output behavior of InP-InGaAlP tunneling injection quantum-dot-well laser

Polarization-resolved amplified spontaneous emission (ASE) and gain from tensile-strained multiple quantum wells (QWs) coupled to a single layer of compressively strained quantum dots (QDs) show interesting output characteristics. Low current injection reveals transverse electric polarized ASE from the QD ground state and QD-coupled-QW state. Additionally, transverse magnetic ASE from the QW state is observed. The modal gain of this laser shows coupled active state activation which is evident by spectral narrowing and change from QW-like to QD-like spectrum.