Scaling behavior of bipolar cascade VCSELs

The Interband Cascade Laser

“…This may considerably reduce the threshold power density, provided the quasi-elastic recycling of carriers from valence to conduction band within each stage does not require much additional voltage or current [63,64]. While the well-known Esaki or tunnel diode [65][66][67] may be used to implement carrier recycling, most ICLs alternatively take advantage of the unusual semimetallic band alignment between the narrow-gap semiconductors InAs and Ga(In)Sb [68,69]. This approach avoids the appreciable mid-IR optical losses, especially due to free hole absorption, that occurs if every stage incorporates a heavily-doped tunnel junction.…”

Three-terminal dual-stage vertical-cavity surface-emitting laser

“…The successful research into conventional vertical-cavity surface-emitting lasers (VCSELs) at 850 nm wavelength has led to mass-production of these devices for commercial shortdistance high-speed and parallel optical data communication systems. Today, the research is mainly focused on the development of reliable 1.3 and 1.55 µm VCSELs but also on the realization and investigation of new design concepts to overcome the bottlenecks of standard VCSELs such as tunability [1], singlemode power [2], dynamic behavior [3] and roundtrip gain [4]. In this letter we present the experimental results on a fabricated three-terminal dual-stage p-n-p VCSEL at 980 nm wavelength.…”

Bistability in bipolar cascade VCSELs

“…For the first time to our knowledge, in this article, measurement results are reported on the bistable behavior of bipolar cascade VCSELs, exploiting the saturable absorption effect. Bipolar cascade VCSELs, in general, have been successfully demonstrated to overcome the bottleneck of limited roundtrip gain in vertical laser resonators due to carrier recycling [8]. However, since the active regions in cascade lasers are electrically coupled, current spreading in the cavity leads to non-homogeneously pumped stages which can favor bistable behavior.…”