Low threshold electrically pumped red emitting InP/Al0.20GaInP quantum dot vertical microcavity laser

In this contribution we report on the fabrication and the emission characteristics of electrically pumped QDs embedded in monolithically grown microcavity p-i-n-diode structures in the InP/AlGalnP material system. By incorporation of an oxide aperture with small diameter the current path in the QD VCSEL was strongly confined so that optical transverse modes appear. We can clearly see the laser emission line at around 1.9 eV at room temperature. High-resolution electroluminescence (EL) measurements of the peak resolve clearly a large number of higher transverse modes at the high energy side of the fundamental laser mode. Further lasers also with smaller oxide aperture diameters show similar behavior, but with larger transverse mode spacing as expected for smaller mode volumes.