Moving from ultrafast VECSELs to MIXSELs: a new class of ultrafast semiconductor lasers

摘要

We demonstrate wafer-scale integration of a saturable absorber in a surface emitting semiconductor laser. Vertical external cavity surface-emitting lasers (VECSELs) have high quality circular output beams, 2D-array scalability, and high average power. To date, ultrafast VECSELs required a folded cavity with a separate saturable absorber device for passive modelocking. In the result presented here, we integrate the saturable absorber into the same semiconductor wafer, optimize its performance for integration with quantum dots and demonstrate stable passive modelocking in a simple straight external cavity which allows for a fully monolithically wafer-integrated structure to reduce cost and improve ease of mass production. We refer to this class of devices as the modelocked integrated external-cavity surface emitting laser (MIXSEL). Such devices would be ideally suited for many applications where the current ultrafast laser technology is considered to be too bulky and expensive.