Optical gain properties of InAs∕InAlGaAs∕InP quantum dash structures with a spectral gain bandwidth of more than 300nm

The excellent wavelength tuning properties of InP-based quantum dash (QDash) layer structures were used to realize ultrawide-gain bandwidth lasers for applications in the 1.55μm telecommunication range. To expand the attainable gain bandwidth six QDash layers with three different emission wavelengths were combined in a laser structure. Broad area laser evaluation reveals good device performance. Within the optical telecommunication band at 1.55μm a gain bandwidth of more than 300nm could be experimentally confirmed, which is in good quantitative agreement with theoretical predictions by taking into account an inhomogeneous carrier distribution between the different dash layers.